[SCSI] qla2xxx: Initialize payload receive length in failure path of vendor commands

Since bsg_job->reply->reply_payload_rcv_len is uninitialized
in case of failure, fc-transport triggers a warning for each command
failed.

Cc: stable@kernel.org
Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>