MIPS: IP22/IP28: Fix build of EISA code.

  CC      arch/mips/sgi-ip22/ip22-eisa.o
/home/ralf/src/linux/linux-mips/arch/mips/sgi-ip22/ip22-eisa.c: In function ‘ip22_eisa_intr’:
/home/ralf/src/linux/linux-mips/arch/mips/sgi-ip22/ip22-eisa.c:77:11: error: variable ‘dma2’ set but not used [-Werror=unused-but-set-variable]
/home/ralf/src/linux/linux-mips/arch/mips/sgi-ip22/ip22-eisa.c:77:5: error: variable ‘dma1’ set but not used [-Werror=unused-but-set-variable]
cc1: all warnings being treated as errors

This warning exists in gcc 4.6.0 and newer.  Kernels 2.6.40 and newer use
-Wunused-but-set-variable to suppress it.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/sgi-ip22/ip22-eisa.c b/arch/mips/sgi-ip22/ip22-eisa.c
index da44ccb..4a6057b 100644
--- a/arch/mips/sgi-ip22/ip22-eisa.c
+++ b/arch/mips/sgi-ip22/ip22-eisa.c
@@ -73,12 +73,10 @@
 
 static irqreturn_t ip22_eisa_intr(int irq, void *dev_id)
 {
-	u8 eisa_irq;
-	u8 dma1, dma2;
+	u8 eisa_irq = inb(EIU_INTRPT_ACK);
 
-	eisa_irq = inb(EIU_INTRPT_ACK);
-	dma1 = inb(EISA_DMA1_STATUS);
-	dma2 = inb(EISA_DMA2_STATUS);
+	inb(EISA_DMA1_STATUS);
+	inb(EISA_DMA2_STATUS);
 
 	if (eisa_irq < EISA_MAX_IRQ) {
 		do_IRQ(eisa_irq);