smb: server: queue post_recv_credits_work in put_recvmsg() and avoid count_avail_recvmsg

smb: server: queue post_recv_credits_work in put_recvmsg() and avoid count_avail_recvmsg

This is basically what the client is doing in put_receive_buffer().

It means we don't need complicated work to maintain count_avail_recvmsg.

But we keep the logic to queue post_recv_credits_work if the
peer raises the requested credit_target and put_receive_buffer()
is not called.

Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>