scsi: st: remove unneeded variable 'result' in st_release()

Also remove a strange '^L' after this function.

Fix the following coccicheck warning:

drivers/scsi/st.c:1460:5-11: Unneeded variable: "result". Return "0" on
line 1473

Link: https://lore.kernel.org/r/20200418070605.11450-1-yanaijie@huawei.com


Reported-by: Hulk Robot <hulkci@huawei.com>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>