libceph: directly skip to the end of redirect reply

Coverity complains about a double write to *p.  Don't bother with
osd_instructions and directly skip to the end of redirect reply.
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

net/ceph/osd_client.c

@@ -3483,9 +3483,6 @@ static int ceph_redirect_decode(void **p, void *end,
 		goto e_inval;
 	}
 
-	len = ceph_decode_32(p);
-	*p += len; /* skip osd_instructions */
-
 	/* skip the rest */
 	*p = struct_end;
 out: