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>

init/initramfs.c

@@ -515,6 +515,7 @@ static void __init free_initrd(void)
 	initrd_end = 0;
 }
 
+#ifdef CONFIG_BLK_DEV_RAM
 #define BUF_SIZE 1024
 static void __init clean_rootfs(void)
 {
@@ -561,6 +562,7 @@ static void __init clean_rootfs(void)
 	sys_close(fd);
 	kfree(buf);
 }
+#endif
 
 static int __init populate_rootfs(void)
 {