board/gw8260/flash.c: Fix GCC 4.6 build warning

Fix:
flash.c: In function 'flash_init':
flash.c:81:16: warning: variable 'size' set but not used
[-Wunused-but-set-variable]

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Oliver Brown <obrown@adventnetworks.com>
diff --git a/board/gw8260/flash.c b/board/gw8260/flash.c
index c1c26ea..fb29659 100644
--- a/board/gw8260/flash.c
+++ b/board/gw8260/flash.c
@@ -78,7 +78,6 @@
  */
 unsigned long flash_init(void)
 {
-	unsigned long size;
 	int i;
 
 	/* Init: no FLASHes known */
@@ -86,7 +85,7 @@
 		flash_info[i].flash_id = FLASH_UNKNOWN;
 
 	/* for now, only support the 4 MB Flash SIMM */
-	size = flash_get_size((vu_long *) CONFIG_SYS_FLASH0_BASE,
+	(void)flash_get_size((vu_long *) CONFIG_SYS_FLASH0_BASE,
 			      &flash_info[0]);
 	/*
 	 * protect monitor and environment sectors