Octave: error() must be called with an argument

Examples/test-suite/octave/multi_import_runme.m

@@ -8,22 +8,22 @@ multi_import_b;
 
 x = multi_import_b.XXX();
 if (x.testx() != 0)
-  error
+  error("failed");
 endif
 
 y = multi_import_b.YYY();
 if (y.testx() != 0)
-  error
+  error("failed");
 endif
 if (y.testy() != 1)
-  error
+  error("failed");
 endif
 
 z = multi_import_a.ZZZ();
 if (z.testx() != 0)
-  error
+  error("failed");
 endif
 if (z.testz() != 2)
-  error
+  error("failed");
 endif