arm, bootm: Fix compile warning

Fix warning:

bootm.c: In function 'bootm_linux_fdt':
bootm.c:181: warning: unused variable 's'
bootm.c:180: warning: unused variable 'bd'

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index 2e7b2e1..a1649ee 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -177,8 +177,6 @@
 static int bootm_linux_fdt(int machid, bootm_headers_t *images)
 {
 	ulong rd_len;
-	bd_t *bd = gd->bd;
-	char *s;
 	void (*kernel_entry)(int zero, int dt_machid, void *dtblob);
 	ulong bootmap_base = getenv_bootm_low();
 	ulong of_size = images->ft_len;