swscale-test: merge declaration and initialization

Originally committed as revision 31879 to svn://svn.mplayerhq.hu/mplayer/trunk/libswscale

libswscale/swscale-test.c

@@ -82,9 +82,8 @@ static int doTest(uint8_t *ref[4], int refStride[4], int w, int h,
     int i;
     uint64_t ssdY, ssdU=0, ssdV=0, ssdA=0;
     struct SwsContext *dstContext = NULL, *outContext = NULL;
-    int res;
+    int res = 0;
 
-    res = 0;
     for (i=0; i<4; i++) {
         // avoid stride % bpp != 0
         if (dstFormat==PIX_FMT_RGB24 || dstFormat==PIX_FMT_BGR24)