svq1enc: check ff_get_buffer() return value

Fixes CID747723
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/svq1enc.c

@@ -547,8 +547,10 @@ static int svq1_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
     }
 
     if (!s->current_picture.data[0]) {
-        ff_get_buffer(avctx, &s->current_picture);
-        ff_get_buffer(avctx, &s->last_picture);
+        if ((ret = ff_get_buffer(avctx, &s->current_picture) < 0) ||
+            (ret = ff_get_buffer(avctx, &s->last_picture))   < 0) {
+            return ret;
+        }
         s->scratchbuf = av_malloc(s->current_picture.linesize[0] * 16 * 2);
     }