[SCSI] be2iscsi: fix boot hang due to interrupts not getting rearmed

This patch fixes a bug where the interrupts were not rearmed if
the Interrupt Mask was enabled. This patch checks for Interrupt mask
enabled and still rearms interrupt generation even if the Interrupt
mask was enabled

Signed-off-by: Jayamohan Kallickal <jayamohan.kallickal@emulex.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>