Clear task management bits when preparing SCSI commands

In lpfc_scsi_prep_cmnd, clear the task management bits (fcpCntl2 member
in the fcp_cmd structure) when preparing regular SCSI commands.
Signed-off-by: James Smart <James.Smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>