avformat/sctp: close socket on errors

This is untested as i have no testcase

Fixes: CID1302709

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit c9a2996544)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/sctp.c

@@ -282,6 +282,8 @@ fail:
         goto restart;
     }
 fail1:
+    if (fd >= 0)
+        closesocket(fd);
     ret = AVERROR(EIO);
     freeaddrinfo(ai);
     return ret;