audit: fix dangling keywords in integrity ima message output

Replace spaces in op keyword labels in log output since userspace audit tools
can't parse orphaned keywords.
Reported-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

security/integrity/ima/ima_appraise.c

@@ -214,7 +214,7 @@ int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
 		hash_start = 1;
 	case IMA_XATTR_DIGEST:
 		if (iint->flags & IMA_DIGSIG_REQUIRED) {
-			cause = "IMA signature required";
+			cause = "IMA-signature-required";
 			status = INTEGRITY_FAIL;
 			break;
 		}

security/integrity/ima/ima_policy.c

@@ -332,7 +332,7 @@ void __init ima_init_policy(void)
 void ima_update_policy(void)
 {
 	static const char op[] = "policy_update";
-	const char *cause = "already exists";
+	const char *cause = "already-exists";
 	int result = 1;
 	int audit_info = 0;
 
@@ -659,7 +659,7 @@ ssize_t ima_parse_add_rule(char *rule)
 	/* Prevent installed policy from changing */
 	if (ima_rules != &ima_default_rules) {
 		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
-				    NULL, op, "already exists",
+				    NULL, op, "already-exists",
 				    -EACCES, audit_info);
 		return -EACCES;
 	}
@@ -685,7 +685,7 @@ ssize_t ima_parse_add_rule(char *rule)
 	if (result) {
 		kfree(entry);
 		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
-				    NULL, op, "invalid policy", result,
+				    NULL, op, "invalid-policy", result,
 				    audit_info);
 		return result;
 	}