[SCSI] qla2xxx: Fix "occured" spelling errors.

Fix "occured" spelling errors.  Most of these are in comments, which
I wouldn't normally bother with, but a couple are in printks, which
irritate me more.  So I just fixed them all at the same time.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>