apparmor: Use sysfs_emit in param_get_{audit,mode}

apparmor: Use sysfs_emit in param_get_{audit,mode}

Replace sprintf() with sysfs_emit() in param_get_audit() and
param_get_mode(). sysfs_emit() is preferred for formatting sysfs output
because it provides safer bounds checking.  Add terminating newlines as
suggested by checkpatch.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: John Johansen <john.johansen@canonical.com>