Add some braces to silence the warning:

libavcodec/vp8.c:892: warning: suggest explicit braces to avoid ambiguous `else'

Originally committed as revision 24366 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/vp8.c

@@ -889,9 +889,9 @@ else      AV_COPY64(b,a);
     XCHG(top_border_m1+8, src_y-8, xchg);
     XCHG(top_border,      src_y,   xchg);
     XCHG(top_border+8,    src_y+8, 1);
-    if (mb_x < mb_width-1)
+    if (mb_x < mb_width-1) {
         XCHG(top_border+32, src_y+16, 1);
-
+    }
     // only copy chroma for normal loop filter
     // or to initialize the top row to 127
     if (!simple || !mb_y) {