scsi: core: Fix formatting errors in scsi_lib.c

Delete trailing whitespace, multiple blank lines, and make switch/case be
at the same indentation.

Link: https://lore.kernel.org/r/20200619154117.10262-3-huobean@gmail.com


Signed-off-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>