apparmor: exec should not be returning ENOENT when it denies

The current behavior is confusing as it causes exec failures to report
the executable is missing instead of identifying that apparmor
caused the failure.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>

security/apparmor/domain.c

@@ -433,7 +433,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
 				new_profile = aa_get_newest_profile(ns->unconfined);
 				info = "ux fallback";
 			} else {
-				error = -ENOENT;
+				error = -EACCES;
 				info = "profile not found";
 				/* remove MAY_EXEC to audit as failure */
 				perms.allow &= ~MAY_EXEC;