[php] Ensure _runme.php calls check::done()

This function doesn't do anything currently so these missing calls are a
latent issue.  It could be used for e.g. memory leak checking in the
future though, and it's potentially a useful place to add code when
debugging.

Examples/test-suite/php/swig_exception_runme.php

@@ -28,3 +28,5 @@ $e = NULL;
 if (Shape::nshapes() != 0) {
     check::fail("Shape::nshapes() should be 0, actually ".Shape::nshapes());
 }
+
+check::done();