fs/binfmt_misc.c: add terminating newline to /proc/sys/fs/binfmt_misc/status

The following is what it looks like before patching.
It is not much readable.

user@ubuntu:/proc/sys/fs/binfmt_misc$ cat status
enableduser@ubuntu:/proc/sys/fs/binfmt_misc$

Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>