Merge pull request #132 from Pan7/SDL_Init

SDL_Init zero check

code/sdl/sdl_glimp.c

@@ -516,7 +516,7 @@ static qboolean GLimp_StartDriverAndSetMode(int mode, qboolean fullscreen, qbool
 	{
 		const char *driverName;
 
-		if (SDL_Init(SDL_INIT_VIDEO) == -1)
+		if (SDL_Init(SDL_INIT_VIDEO) != 0)
 		{
 			ri.Printf( PRINT_ALL, "SDL_Init( SDL_INIT_VIDEO ) FAILED (%s)\n", SDL_GetError());
 			return qfalse;