Reverted 3d2e5a0b66

Applying these changes to external code doesn't actually improve anything, and within the context of the other Get* functions for renderers and surfaces, these stand out as outliers, so I'm going to back this change out.

test/testshader.c

@@ -332,7 +332,7 @@ SDL_GL_LoadTexture(SDL_Surface *surface, GLfloat *texcoord)
     }
 
     /* Save the alpha blending attributes */
-    saved_mode = SDL_GetSurfaceBlendMode(surface);
+    SDL_GetSurfaceBlendMode(surface, &saved_mode);
     SDL_SetSurfaceBlendMode(surface, SDL_BLENDMODE_NONE);
 
     /* Copy the surface into the GL texture image */