Fail to build with GCC 14

[marillat]

Debian amd64
GCC 14.2.0
Also, a good idea to fix warnings.

In file included from vumeter.c:37:
fastftoi.h:121: warning: ignoring '#pragma warning ' [-Wunknown-pragmas]
  121 | #pragma warning "using sse2 for ftoi"
vumeter.c: In function 'vumeter_draw_retro':
vumeter.c:833:19: warning: unused variable 'sz' [-Wunused-variable]
  833 |         const int sz = snprintf (path, PATH_MAX, "/usr/share/deadbeef/vumeter.png");
      |                   ^~
In file included from /usr/lib/x86_64-linux-gnu/glib-2.0/include/glibconfig.h:9,
                 from /usr/include/glib-2.0/glib/gtypes.h:34,
                 from /usr/include/glib-2.0/glib/galloca.h:34,
                 from /usr/include/glib-2.0/glib.h:32,
                 from /usr/include/gtk-3.0/gdk/gdkconfig.h:8,
                 from /usr/include/gtk-3.0/gdk/gdk.h:30,
                 from /usr/include/gtk-3.0/gtk/gtk.h:30,
                 from vumeter.c:32:
vumeter.c: In function 'vumeter_draw_bars':
/usr/include/glib-2.0/glib/gmacros.h:929:17: error: 'return' with a value, in function returning void [-Wreturn-mismatch]
  929 | #define FALSE   (0)
      |                 ^
vumeter.c:875:16: note: in expansion of macro 'FALSE'
  875 |         return FALSE;
      |                ^~~~~
vumeter.c:856:1: note: declared here
  856 | vumeter_draw_bars (w_vumeter_t *w, cairo_t *cr, int width, int height)
      | ^~~~~~~~~~~~~~~~~
vumeter.c: In function 'vumeter_draw':
vumeter.c:965:43: warning: comparison between 'ddb_playback_state_t' {aka 'enum ddb_playback_state_e'} and 'enum output_state_t' [-Wenum-compare]
  965 |     if (deadbeef->get_output ()->state () == OUTPUT_STATE_PLAYING) {
      |                                           ^~
vumeter.c: In function 'vumeter_expose_event':
vumeter.c:1033:5: warning: 'gdk_cairo_create' is deprecated: Use 'gdk_window_begin_draw_frame() and gdk_drawing_context_get_cairo_context()' instead [-Wdeprecated-declarations]
 1033 |     cairo_t *cr = gdk_cairo_create (gtk_widget_get_window (widget));
      |     ^~~~~~~
In file included from /usr/include/gtk-3.0/gdk/gdk.h:33:
/usr/include/gtk-3.0/gdk/gdkcairo.h:35:12: note: declared here
   35 | cairo_t  * gdk_cairo_create             (GdkWindow          *window);
      |            ^~~~~~~~~~~~~~~~
vumeter.c: In function 'vumeter_button_release_event':
vumeter.c:1055:7: warning: 'gtk_menu_popup' is deprecated: Use '(gtk_menu_popup_at_widget, gtk_menu_popup_at_pointer, gtk_menu_popup_at_rect)' instead [-Wdeprecated-declarations]
 1055 |       gtk_menu_popup (GTK_MENU (w->popup), NULL, NULL, NULL, w->drawarea, 0, gtk_get_current_event_time ());
      |       ^~~~~~~~~~~~~~
In file included from /usr/include/gtk-3.0/gtk/gtklabel.h:34,
                 from /usr/include/gtk-3.0/gtk/gtkaccellabel.h:35,
                 from /usr/include/gtk-3.0/gtk/gtk.h:33:
/usr/include/gtk-3.0/gtk/gtkmenu.h:138:12: note: declared here
  138 | void       gtk_menu_popup                 (GtkMenu             *menu,
      |            ^~~~~~~~~~~~~~
vumeter.c: In function 'vumeter_message':
vumeter.c:1071:51: warning: comparison between 'ddb_playback_state_t' {aka 'enum ddb_playback_state_e'} and 'enum output_state_t' [-Wenum-compare]
 1071 |             if (deadbeef->get_output ()->state () == OUTPUT_STATE_PLAYING) {
      |                                                   ^~
vumeter.c: In function 'w_vu_meter_create':
vumeter.c:1147:39: error: passing argument 2 of 'deadbeef->vis_waveform_listen' from incompatible pointer type [-Wincompatible-pointer-types]
 1147 |     deadbeef->vis_waveform_listen (w, vumeter_wavedata_listener);
      |                                       ^~~~~~~~~~~~~~~~~~~~~~~~~
      |                                       |
      |                                       void (*)(void *, ddb_audio_data_t *) {aka void (*)(void *, struct ddb_audio_data_s *)}
vumeter.c:1147:39: note: expected 'void (*)(void *, const ddb_audio_data_t *)' {aka 'void (*)(void *, const struct ddb_audio_data_s *)'} but argument is of type 'void (*)(void *, ddb_audio_data_t *)' {aka 'void (*)(void *, struct ddb_audio_data_s *)'}
make[2]: *** [Makefile:84: gtk3/vumeter.o] Error 1
make[2]: Leaving directory '/build/deadbeef-vu-meter-dmo-0.0~20170922'
make[1]: *** [debian/rules:7: override_dh_auto_build] Error 2
make[1]: Leaving directory '/build/deadbeef-vu-meter-dmo-0.0~20170922'
make: *** [debian/rules:4: binary] Error 2