kill a warning on 64-bit machines

Originally committed as revision 9331 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/dsputil.c

@@ -3821,7 +3821,7 @@ int ff_check_alignment(void){
     static int did_fail=0;
     DECLARE_ALIGNED_16(int, aligned);
 
-    if((int)&aligned & 15){
+    if((long)&aligned & 15){
         if(!did_fail){
 #if defined(HAVE_MMX) || defined(HAVE_ALTIVEC)
             av_log(NULL, AV_LOG_ERROR,