audit: allow matching on obj_uid

Allow syscall exit filter matching based on the uid of the owner of an
inode used in a syscall.  aka:

auditctl -a always,exit -S open -F obj_uid=0 -F perm=wa

Signed-off-by: Eric Paris <eparis@redhat.com>

kernel/auditfilter.c

@@ -461,6 +461,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 		case AUDIT_ARG1:
 		case AUDIT_ARG2:
 		case AUDIT_ARG3:
+		case AUDIT_OBJ_UID:
 			break;
 		case AUDIT_ARCH:
 			entry->rule.arch_f = f;