init/initramfs: fix warning with CONFIG_BLK_DEV_RAM=n

init/initramfs.c:520: warning: 'clean_rootfs' defined but not used

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
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 80cd713..e44f2d9 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -515,6 +515,7 @@
 	initrd_end = 0;
 }
 
+#ifdef CONFIG_BLK_DEV_RAM
 #define BUF_SIZE 1024
 static void __init clean_rootfs(void)
 {
@@ -561,6 +562,7 @@
 	sys_close(fd);
 	kfree(buf);
 }
+#endif
 
 static int __init populate_rootfs(void)
 {