ecore: Fix coverity resource leak

Coverity CID1377544 reports that poller is leaked here if we error out
and return null. As poller is created with calloc, we should free it
before returning.

@fix

Signed-off-by: Chris Michael <cp.michael@samsung.com>

src/lib/ecore/ecore_poller.c

@@ -254,6 +254,7 @@ ecore_poller_add(Ecore_Poller_Type type EINA_UNUSED,
    if (!func)
      {
         ERR("callback function must be set up for an object of class: '%s'", MY_CLASS_NAME);
+        free(poller);
         return NULL;
      }