smb: client: queue post_recv_credits_work also if the peer raises the credit target

smb: client: queue post_recv_credits_work also if the peer raises the credit target

This is already handled in the server, but currently it done
in a very complex way there. So we do it much simpler.

Note that put_receive_buffer() will take care of it
in case data_length is 0.

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