board/mpl/common/isa.c: Fix GCC 4.6 build warnings

Fix:
../common/isa.c: In function 'handle_isa_int':
../common/isa.c:385:21: warning: variable 'isr2' set but not used
[-Wunused-but-set-variable]
../common/isa.c:385:16: warning: variable 'isr1' set but not used
[-Wunused-but-set-variable]

Signed-off-by: David Mueller <d.mueller@elsoft.ch>

board/mpl/common/isa.c

@@ -382,12 +382,12 @@ void init_8259A(void)
 int handle_isa_int(void)
 {
 	unsigned long irqack;
-	unsigned char isr1,isr2,irq;
+	unsigned char irq;
 	/* first we acknokledge the int via the PCI bus */
 	irqack=in32(PCI_INT_ACK_ADDR);
 	/* now we get the ISRs */
-	isr2=in8(ISR_2);
-	isr1=in8(ISR_1);
+	in8(ISR_2);
+	in8(ISR_1);
 	irq=(unsigned char)irqack;
 	irq-=32;
 /*	if((irq==7)&&((isr1&0x80)==0)) {