[SCSI] be2iscsi: Fixing the return type of functions

Fixing some functions return values that did not match with
the possible return values

Signed-off-by: Jayamohan Kallickal <jayamohank@serverengines.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>