initramfs: avoid "label at end of compound statement" error

Commit 17a9be31 ("initramfs: Always do fput() and load modules after
rootfs populate") introduced an error for the

    CONFIG_BLK_DEV_RAM=y

case, because even though the code looks fine, the compiler really wants
a statement after a label, or you'll get complaints:

  init/initramfs.c: In function 'populate_rootfs':
  init/initramfs.c:644:2: error: label at end of compound statement

That commit moved the subsequent statements to outside the compound
statement, leaving the label without any associated statements.
Reported-by: NJörg Otte <jrg.otte@gmail.com>
Fixes: 17a9be31 ("initramfs: Always do fput() and load modules after rootfs populate")
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: stable@vger.kernel.org  # if 17a9be31 gets backported
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

init/initramfs.c

@@ -642,6 +642,7 @@ static int __init populate_rootfs(void)
 			free_initrd();
 		}
 	done:
+		/* empty statement */;
 #else
 		printk(KERN_INFO "Unpacking initramfs...\n");
 		err = unpack_to_rootfs((char *)initrd_start,