MIPS: JZ4740: Fix GCC 4.6.0 build error.

CC      arch/mips/jz4740/dma.o
arch/mips/jz4740/dma.c: In function 'jz4740_dma_chan_irq':
arch/mips/jz4740/dma.c:245:11: error: variable 'status' set but not used [-Werro
r=unused-but-set-variable]

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

arch/mips/jz4740/dma.c

@@ -242,9 +242,7 @@ EXPORT_SYMBOL_GPL(jz4740_dma_get_residue);
 
 static void jz4740_dma_chan_irq(struct jz4740_dma_chan *dma)
 {
-	uint32_t status;
-
-	status = jz4740_dma_read(JZ_REG_DMA_STATUS_CTRL(dma->id));
+	(void) jz4740_dma_read(JZ_REG_DMA_STATUS_CTRL(dma->id));
 
 	jz4740_dma_write_mask(JZ_REG_DMA_STATUS_CTRL(dma->id), 0,
 		JZ_DMA_STATUS_CTRL_ENABLE | JZ_DMA_STATUS_CTRL_TRANSFER_DONE);