Use fallthrough statement attribute

lib/hx509/cert.c

@@ -2438,8 +2438,10 @@ hx509_verify_path(hx509_context context,
 		 * EE checking below.
 		 */
 		type = EE_CERT;
+                fallthrough
                 /* FALLTHROUGH */
 	    }
+            fallthrough
 	}
         /* FALLTHROUGH */
 	case EE_CERT:

lib/hx509/cms.c

@@ -182,6 +182,7 @@ fill_CMSIdentifier(const hx509_cert cert,
 						   &id->u.subjectKeyIdentifier);
 	if (ret == 0)
 	    break;
+        fallthrough
 	/* FALLTHROUGH */
     case CMS_ID_NAME: {
 	hx509_name name;

lib/hx509/file.c

@@ -230,6 +230,7 @@ hx509_pem_read(hx509_context context,
 		where = INDATA;
 		goto indata;
 	    }
+            fallthrough
 	    /* FALLTHROUGH */
 	case INHEADER:
 	    if (buf[0] == '\0') {