init: fix possible format string bug

Use constant format string in case message changes.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/init/initramfs.c b/init/initramfs.c
index a67ef9d..93b6139 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -583,7 +583,7 @@
 {
 	char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
 	if (err)
-		panic(err);	/* Failed to decompress INTERNAL initramfs */
+		panic("%s", err); /* Failed to decompress INTERNAL initramfs */
 	if (initrd_start) {
 #ifdef CONFIG_BLK_DEV_RAM
 		int fd;