apparmorfs: Use seq_putc() in two functions

Two single characters (line breaks) should be put into a sequence.
Thus use the corresponding function "seq_putc".

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: John Johansen <john.johansen@canonical.com>