video: Fixed remaining `return 0` to use NULL in CreateDevice implementations.

src/video/emscripten/SDL_emscriptenvideo.c

@@ -62,7 +62,7 @@ static SDL_VideoDevice *Emscripten_CreateDevice(void)
     /* Initialize all variables that we clean on shutdown */
     device = (SDL_VideoDevice *)SDL_calloc(1, sizeof(SDL_VideoDevice));
     if (!device) {
-        return 0;
+        return NULL;
     }
 
     /* Firefox sends blur event which would otherwise prevent full screen

src/video/n3ds/SDL_n3dsvideo.c

@@ -79,7 +79,7 @@ static SDL_VideoDevice *N3DS_CreateDevice(void)
     /* Initialize all variables that we clean on shutdown */
     device = (SDL_VideoDevice *)SDL_calloc(1, sizeof(SDL_VideoDevice));
     if (!device) {
-        return 0;
+        return NULL;
     }
 
     /* Initialize internal data */

src/video/ngage/SDL_ngagevideo.cpp

@@ -105,14 +105,14 @@ static SDL_VideoDevice *NGAGE_CreateDevice(void)
     /* Initialize all variables that we clean on shutdown */
     device = (SDL_VideoDevice *)SDL_calloc(1, sizeof(SDL_VideoDevice));
     if (!device) {
-        return 0;
+        return NULL;
     }
 
     /* Initialize internal N-Gage specific data */
     phdata = (SDL_VideoData *)SDL_calloc(1, sizeof(SDL_VideoData));
     if (!phdata) {
         SDL_free(device);
-        return 0;
+        return NULL;
     }
 
     /* General video */

src/video/ps2/SDL_ps2video.c

@@ -96,7 +96,7 @@ static SDL_VideoDevice *PS2_CreateDevice(void)
     /* Initialize all variables that we clean on shutdown */
     device = (SDL_VideoDevice *)SDL_calloc(1, sizeof(SDL_VideoDevice));
     if (!device) {
-        return 0;
+        return NULL;
     }
 
     /* Set the function pointers */

src/video/riscos/SDL_riscosvideo.c

@@ -58,7 +58,7 @@ static SDL_VideoDevice *RISCOS_CreateDevice(void)
     /* Initialize all variables that we clean on shutdown */
     device = (SDL_VideoDevice *)SDL_calloc(1, sizeof(SDL_VideoDevice));
     if (!device) {
-        return 0;
+        return NULL;
     }
 
     /* Initialize internal data */

src/video/winrt/SDL_winrtvideo.cpp

@@ -108,13 +108,13 @@ static SDL_VideoDevice *WINRT_CreateDevice(void)
     /* Initialize all variables that we clean on shutdown */
     device = (SDL_VideoDevice *)SDL_calloc(1, sizeof(SDL_VideoDevice));
     if (!device) {
-        return 0;
+        return NULL;
     }
 
     data = (SDL_VideoData *)SDL_calloc(1, sizeof(SDL_VideoData));
     if (!data) {
         SDL_free(device);
-        return 0;
+        return NULL;
     }
     device->driverdata = data;