When passing a large read to receive_encrypted_read(), ensure that the
demultiplex_thread knows that a MID was processed.  Without this, those
operations never complete.

This is a similar issue/fix to lease break handling:
commit 7af929d6
("smb3: fix lease break problem introduced by compounding")

CC: Stable <stable@vger.kernel.org> # 4.19+
Fixes: b24df3e3 ("cifs: update receive_encrypted_standard to handle compounded responses")
Signed-off-by: NPaul Aurich <paul@darkrain42.org>
Tested-by: NYves-Alexis Perez <corsac@corsac.net>
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>