libceph: use %s instead of %pE in dout()s

Commit d30291b985 ("libceph: variable-sized ceph_object_id") changed
dout()s in what is now encode_request() and ceph_object_locator_to_pg()
to use %pE, mostly to document that, although all rbd and cephfs object
names are NULL-terminated strings, ceph_object_id will handle any RADOS
object name, including the one containing NULs, just fine.

However, it turns out that vbin_printf() can't handle anything but ints
and %s - all %p suffixes are ignored.  The buffer %p** points to isn't
recorded, resulting in trash in the messages if the buffer had been
reused by the time bstr_printf() got to it.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

net/ceph/osd_client.c

@@ -1539,9 +1539,9 @@ static void encode_request(struct ceph_osd_request *req, struct ceph_msg *msg)
 	 */
 	msg->hdr.data_off = cpu_to_le16(req->r_data_offset);
 
-	dout("%s req %p oid %*pE oid_len %d front %zu data %u\n", __func__,
-	     req, req->r_t.target_oid.name_len, req->r_t.target_oid.name,
-	     req->r_t.target_oid.name_len, msg->front.iov_len, data_len);
+	dout("%s req %p oid %s oid_len %d front %zu data %u\n", __func__,
+	     req, req->r_t.target_oid.name, req->r_t.target_oid.name_len,
+	     msg->front.iov_len, data_len);
 }
 
 /*