[SCSI] qla4xxx: fix recovery timer and session unblock race

If qla4xxx is resetting up a session and the recovery timer
fires we do not want to just set it to dead, because
the dpc thread could have just set it to online and is in the
middle of resetting it up.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: David Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>