scsi: snic: Make snic_io_exch_ver_cmpl_handler() return void

scsi: snic: Make snic_io_exch_ver_cmpl_handler() return void

This function does not need a return value since no callers depend on
it. Make it return void.

This also fixes the coccicheck warning:

drivers/scsi/snic/snic_ctl.c:163:5-8: Unneeded variable: "ret". Return
"0" on line 228

Link: https://lore.kernel.org/r/20200418070615.11603-1-yanaijie@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>