drivers/block/sym53c8xx.c: Fix GCC 4.6 build warning

Fix:
sym53c8xx.c: In function 'scsi_write_dsp':
sym53c8xx.c:456:16: warning: variable 'val' set but not used
[-Wunused-but-set-variable]

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/drivers/block/sym53c8xx.c b/drivers/block/sym53c8xx.c
index 8094b41..564aa98 100644
--- a/drivers/block/sym53c8xx.c
+++ b/drivers/block/sym53c8xx.c
@@ -453,11 +453,9 @@
 
 void scsi_write_dsp(unsigned long start)
 {
-	unsigned long val;
 #ifdef SCSI_SINGLE_STEP
 	unsigned char t;
 #endif
-	val = start;
 	out32r(scsi_mem_addr + DSP,start);
 #ifdef SCSI_SINGLE_STEP
 	t=scsi_read_byte(DCNTL);