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 <[e-mail]>
Signed-off-by: Ilya Dryomov <[e-mail]>

net/ceph/osd_client.c

···
 		goto e_inval;
 	}
 
-	len = ceph_decode_32(p);
-	*p += len; /* skip osd_instructions */
-
 	/* skip the rest */
 	*p = struct_end;
 out: