Fixed warning C6340: Mismatch on sign: 'int' passed as _Param_(3) when some unsigned type is required in call to 'SDL_sscanf_REAL'.

src/video/SDL_blit.c

@@ -126,7 +126,7 @@ static SDL_BlitFunc SDL_ChooseBlitFunc(Uint32 src_format, Uint32 dst_format, int
                                        SDL_BlitFuncEntry *entries)
 {
     int i, flagcheck = (flags & (SDL_COPY_MODULATE_COLOR | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND | SDL_COPY_ADD | SDL_COPY_MOD | SDL_COPY_MUL | SDL_COPY_COLORKEY | SDL_COPY_NEAREST));
-    static int features = 0x7fffffff;
+    static unsigned int features = 0x7fffffff;
 
     /* Get the available CPU features */
     if (features == 0x7fffffff) {