libceph: update outdated comment in ceph_sock_write_space()

The function try_write() was renamed to ceph_con_v1_try_write()
in commit 566050e ("libceph: separate msgr1 protocol
implementation") and subsequently moved to net/ceph/messenger_v1.c
in commit 2f71361 ("libceph: move msgr1 protocol implementation
to its own file").  Update the comment in ceph_sock_write_space()
accordingly.

[ idryomov: account for msgr2 in the updated comment as well ]

Signed-off-by: kexinsun <kexinsun@smail.nju.edu.cn>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Author: kexinsun

net/ceph/messenger.c

@@ -368,8 +368,8 @@ static void ceph_sock_write_space(struct sock *sk)
 	/* only queue to workqueue if there is data we want to write,
 	 * and there is sufficient space in the socket buffer to accept
 	 * more data.  clear SOCK_NOSPACE so that ceph_sock_write_space()
-	 * doesn't get called again until try_write() fills the socket
-	 * buffer. See net/ipv4/tcp_input.c:tcp_check_space()
+	 * doesn't get called again until ceph_con_v[12]_try_write() fills
+	 * the socket buffer. See net/ipv4/tcp_input.c:tcp_check_space()
 	 * and net/core/stream.c:sk_stream_write_space().
 	 */
 	if (ceph_con_flag_test(con, CEPH_CON_F_WRITE_PENDING)) {