Issue:
For ISP83XX risc_intr getting clear two times in case of polling mode.
risc_intr getting clear from interrupt_service_routine() as well
from process_mbox_intr() because of this driver may clear risc_intr
without processing interrupt.

Fix:
Do not clear risc_intr from process_mbox_intr().
Signed-off-by: NManish Dusane <manish.dusane@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>