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 <[e-mail]>
Signed-off-by: John Johansen <[e-mail]>

security/apparmor/apparmorfs.c

···
 	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"),
 	{ }
 };