CIFS: Fix credit computation for compounded requests

CIFS: Fix credit computation for compounded requests

commit 8544f4aa9dd19a04d1244dae10feecc813ccf175 upstream.

In SMB3 protocol every part of the compound chain consumes credits
individually, so we need to call wait_for_free_credits() for each
of the PDUs in the chain. If an operation is interrupted, we must
ensure we return all credits taken from the server structure back.

Without this patch server can sometimes disconnect the session
due to credit mismatches, especially when first operation(s)
are large writes.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>