[PATCH] applicom: Prevent unsigned wrap in ac_interrupt()

[Roel Kluin <roel.kluin@gmail.com>]

unsigned i wraps if this occurs in the first iteration.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
Or do we know this can't happen?

diff --git a/drivers/char/applicom.c b/drivers/char/applicom.c
index 73a0765..0df3e12 100644
--- a/drivers/char/applicom.c
+++ b/drivers/char/applicom.c
@@ -670,7 +670,7 @@ static irqreturn_t ac_interrupt(int vec, void *dev_instance)
 			}
 			Dummy = readb(apbs[i].RamIO + VERS);
 
-			if(readb(apbs[i].RamIO + RAM_IT_TO_PC)) {
+			if(i && readb(apbs[i].RamIO + RAM_IT_TO_PC)) {
 				/* There's another int waiting on this card */
 				spin_unlock(&apbs[i].mutex);
 				i--;