Declare with av_unused the variable alpMmxFilter, fix the gcc warning:

swscale_template.c: In function ‘swScale_C’:
swscale_template.c:2580: warning: unused variable ‘alpMmxFilter’
swscale_template.c: In function ‘sws_init_swScale_C’:

Originally committed as revision 30332 to svn://svn.mplayerhq.hu/mplayer/trunk/libswscale

libswscale/swscale_template.c

@@ -2577,7 +2577,7 @@ static int RENAME(swScale)(SwsContext *c, const uint8_t* src[], int srcStride[],
     int16_t *hChrFilter= c->hChrFilter;
     int32_t *lumMmxFilter= c->lumMmxFilter;
     int32_t *chrMmxFilter= c->chrMmxFilter;
-    int32_t *alpMmxFilter= c->alpMmxFilter;
+    int32_t av_unused *alpMmxFilter= c->alpMmxFilter;
     const int vLumFilterSize= c->vLumFilterSize;
     const int vChrFilterSize= c->vChrFilterSize;
     const int hLumFilterSize= c->hLumFilterSize;