Fix warnings detected on Android build

src/events/SDL_mouse.c

@@ -545,7 +545,7 @@ SDL_SendMouseWheel(SDL_Window * window, SDL_MouseID mouseID, float x, float y, S
         SDL_SetMouseFocus(window);
     }
 
-    if (!x && !y) {
+    if (x == 0. && y == 0.) {
         return 0;
     }
 

src/events/SDL_touch.c

@@ -315,7 +315,7 @@ SDL_SendTouchMotion(SDL_TouchID id, SDL_FingerID fingerid,
     prel = pressure - finger->pressure;
 
     /* Drop events that don't change state */
-    if (!xrel && !yrel && !prel) {
+    if (xrel == 0. && yrel == 0. && prel == 0.) {
 #if 0
         printf("Touch event didn't change state - dropped!\n");
 #endif