MIPS: Malta: Fix GCC 4.6.0 build error

CC      arch/mips/mti-malta/malta-int.o
arch/mips/mti-malta/malta-int.c: In function 'mips_pcibios_iack':
arch/mips/mti-malta/malta-int.c:59:6: error: variable 'dummy' set but not used [-Werror=unused-but-set-variable]
cc1: all warnings being treated as errors

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/mti-malta/malta-int.c

@@ -56,7 +56,6 @@ static DEFINE_RAW_SPINLOCK(mips_irq_lock);
 static inline int mips_pcibios_iack(void)
 {
 	int irq;
-	u32 dummy;
 
 	/*
 	 * Determine highest priority pending interrupt by performing
@@ -83,7 +82,7 @@ static inline int mips_pcibios_iack(void)
 		BONITO_PCIMAP_CFG = 0x20000;
 
 		/* Flush Bonito register block */
-		dummy = BONITO_PCIMAP_CFG;
+		(void) BONITO_PCIMAP_CFG;
 		iob();    /* sync */
 
 		irq = __raw_readl((u32 *)_pcictrl_bonito_pcicfg);