board/lubbock/flash.c: Fix GCC 4.6 warnings

Fix:
flash.c: In function 'flash_erase':
flash.c:223:6: warning: variable 'flag' set but not used [-Wunused-but-set-variable]
flash.c: In function 'write_data':
flash.c:392:6: warning: variable 'flag' set but not used [-Wunused-but-set-variable]

Signed-off-by: Anatolij Gustschin <agust@denx.de>
diff --git a/board/lubbock/flash.c b/board/lubbock/flash.c
index e1e7807..bf8f0c9 100644
--- a/board/lubbock/flash.c
+++ b/board/lubbock/flash.c
@@ -220,7 +220,7 @@
 
 int flash_erase (flash_info_t *info, int s_first, int s_last)
 {
-	int flag, prot, sect;
+	int prot, sect;
 	ulong type, start;
 	int rcode = 0;
 
@@ -255,7 +255,7 @@
 	}
 
 	/* Disable interrupts which might cause a timeout here */
-	flag = disable_interrupts ();
+	disable_interrupts();
 
 	/* Start erase on unprotected sectors */
 	for (sect = s_first; sect <= s_last; sect++) {
@@ -389,7 +389,6 @@
 {
 	FPWV *addr = (FPWV *) dest;
 	ulong status;
-	int flag;
 	ulong start;
 
 	/* Check if Flash is (sufficiently) erased */
@@ -398,7 +397,7 @@
 		return (2);
 	}
 	/* Disable interrupts which might cause a timeout here */
-	flag = disable_interrupts ();
+	disable_interrupts();
 
 	*addr = (FPW) 0x00400040;	/* write setup */
 	*addr = data;