apparmor: advertise disconnected.path is available

While disconnected.path has been available for a while it was never
properly advertised as a feature. Fix this so that userspace doesn't
need special casing to handle it.
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

security/apparmor/apparmorfs.c

@@ -2336,6 +2336,7 @@ static struct aa_sfs_entry aa_sfs_entry_domain[] = {
 	AA_SFS_FILE_BOOLEAN("post_nnp_subset",	1),
 	AA_SFS_FILE_BOOLEAN("computed_longest_left",	1),
 	AA_SFS_DIR("attach_conditions",		aa_sfs_entry_attach),
+	AA_SFS_FILE_BOOLEAN("disconnected.path",            1),
 	AA_SFS_FILE_STRING("version", "1.2"),
 	{ }
 };