scsi: qla2xxx: Remove unnecessary locking from the target code

All callbacks from the target core into the qla2xxx driver and also all I/O
completion functions are serialized per command. Since .cmd_sent_to_fw and
.trc_flags are only modified from inside these functions it is not
necessary to protect it with locking. Remove the superfluous locking.

Cc: Himanshu Madhani <hmadhani@marvell.com>
Cc: Giridhar Malavali <gmalavali@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>