svq1dec: Unbreak the scratch buffer allocation

The input packets are always assumed to be padded and
the av_fast_ family of function takes a pointer to a pointer.

Thanks to Nicolas Dufresne <nicolas.dufresne@collabora.com> for
a similar patch.

Introduced in 7b588bb691.

Bug-Id: 766
CC: libav-stable@libav.org
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavcodec/svq1dec.c

@@ -637,8 +637,9 @@ static int svq1_decode_frame(AVCodecContext *avctx, void *data,
             return AVERROR_INVALIDDATA;
         }
 
-        av_fast_malloc(s->pkt_swapped, &s->pkt_swapped_allocated,
-                       buf_size);
+        av_fast_padded_malloc(&s->pkt_swapped,
+                              &s->pkt_swapped_allocated,
+                              buf_size);
         if (!s->pkt_swapped)
             return AVERROR(ENOMEM);