mfd: ucb1x00: Allow IRQ probing to work with IRQs > 32

probe_irq_on() only returns non-zero if it found any interrupts below
IRQ32 which could be probe candidates.  If all the probable interrupts
are higher than 32, then this will cause a failure.  Fix this.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/ucb1x00-core.c

@@ -446,10 +446,6 @@ static int ucb1x00_detect_irq(struct ucb1x00 *ucb)
 	unsigned long mask;
 
 	mask = probe_irq_on();
-	if (!mask) {
-		probe_irq_off(mask);
-		return NO_IRQ;
-	}
 
 	/*
 	 * Enable the ADC interrupt.