vo: change vo_platform_init to bool

There's several functions that are used for initializing mpv on a
certain platform (x11, wayland, etc.). These currently are all int, but
they actually return 1 and 0 like a boolean. This gets a bit confusing
because actual vo preinit functions return 0 and -1 instead. Just make
these all bool instead and return true/false to make it clearer.

video/out/android_common.c

@@ -29,7 +29,7 @@ struct vo_android_state {
     ANativeWindow *native_window;
 };
 
-int vo_android_init(struct vo *vo)
+bool vo_android_init(struct vo *vo)
 {
     vo->android = talloc_zero(vo, struct vo_android_state);
     struct vo_android_state *ctx = vo->android;
@@ -51,11 +51,11 @@ int vo_android_init(struct vo *vo)
         goto fail;
     }
 
-    return 1;
+    return true;
 fail:
     talloc_free(ctx);
     vo->android = NULL;
-    return 0;
+    return false;
 }
 
 void vo_android_uninit(struct vo *vo)

video/out/android_common.h

@@ -23,7 +23,7 @@
 
 struct vo;
 
-int vo_android_init(struct vo *vo);
+bool vo_android_init(struct vo *vo);
 void vo_android_uninit(struct vo *vo);
 ANativeWindow *vo_android_native_window(struct vo *vo);
 bool vo_android_surface_size(struct vo *vo, int *w, int *h);

video/out/w32_common.c

@@ -1618,8 +1618,7 @@ done:
     return NULL;
 }
 
-// Returns: 1 = Success, 0 = Failure
-int vo_w32_init(struct vo *vo)
+bool vo_w32_init(struct vo *vo)
 {
     assert(!vo->w32);
 
@@ -1651,11 +1650,11 @@ int vo_w32_init(struct vo *vo)
         talloc_free(profile);
     }
 
-    return 1;
+    return true;
 fail:
     talloc_free(w32);
     vo->w32 = NULL;
-    return 0;
+    return false;
 }
 
 struct disp_names_data {

video/out/w32_common.h

@@ -26,7 +26,7 @@
 
 struct vo;
 
-int vo_w32_init(struct vo *vo);
+bool vo_w32_init(struct vo *vo);
 void vo_w32_uninit(struct vo *vo);
 int vo_w32_control(struct vo *vo, int *events, int request, void *arg);
 void vo_w32_config(struct vo *vo);

video/out/wayland_common.c

@@ -1929,7 +1929,7 @@ int vo_wayland_control(struct vo *vo, int *events, int request, void *arg)
     return VO_NOTIMPL;
 }
 
-int vo_wayland_init(struct vo *vo)
+bool vo_wayland_init(struct vo *vo)
 {
     vo->wl = talloc_zero(NULL, struct vo_wayland_state);
     struct vo_wayland_state *wl = vo->wl;

video/out/wayland_common.h

@@ -153,11 +153,11 @@ struct vo_wayland_state {
 };
 
 bool vo_wayland_check_visible(struct vo *vo);
+bool vo_wayland_init(struct vo *vo);
 bool vo_wayland_supported_format(struct vo *vo, uint32_t format, uint64_t modifier);
 
 int vo_wayland_allocate_memfd(struct vo *vo, size_t size);
 int vo_wayland_control(struct vo *vo, int *events, int request, void *arg);
-int vo_wayland_init(struct vo *vo);
 int vo_wayland_reconfig(struct vo *vo);
 
 void vo_wayland_set_opaque_region(struct vo_wayland_state *wl, int alpha);

video/out/x11_common.c

@@ -596,7 +596,7 @@ static void vo_x11_get_bounding_monitors(struct vo_x11_state *x11, long b[4])
     XFree(screens);
 }
 
-int vo_x11_init(struct vo *vo)
+bool vo_x11_init(struct vo *vo)
 {
     char *dispName;
 
@@ -685,11 +685,11 @@ int vo_x11_init(struct vo *vo)
 
     vo_x11_update_geometry(vo);
 
-    return 1;
+    return true;
 
 error:
     vo_x11_uninit(vo);
-    return 0;
+    return false;
 }
 
 static const struct mp_keymap keymap[] = {

video/out/x11_common.h

@@ -142,7 +142,7 @@ struct vo_x11_state {
     Atom icc_profile_property;
 };
 
-int vo_x11_init(struct vo *vo);
+bool vo_x11_init(struct vo *vo);
 void vo_x11_uninit(struct vo *vo);
 void vo_x11_check_events(struct vo *vo);
 bool vo_x11_screen_is_composited(struct vo *vo);