Make sws_dcVec static: It is only used inside libswscale/utils.c.

git-svn-id: file:///var/local/repositories/mplayer/trunk/libswscale@30787 b3059339-0415-0410-9bf9-f77b7e298cf2

utils.c

@@ -1311,7 +1311,7 @@ SwsVector *sws_getIdentityVec(void)
     return sws_getConstVec(1.0, 1);
 }
 
-double sws_dcVec(SwsVector *a)
+static double sws_dcVec(SwsVector *a)
 {
     int i;
     double sum=0;