scsi: qla2xxx: Fix SRB leak on switch command timeout

when GPSC/GPDB switch command fails, driver just returns without doing a
proper cleanup. This patch fixes this memory leak by calling sp->free() in
the error path.

Link: https://lore.kernel.org/r/20191105150657.8092-4-hmadhani@marvell.com


Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>