docs: Move news.rng out of docs/schemas

docs/schemas directory is meant for schemas which are installed on the
system. The schema for the news file does not need to be installed.
Store it along with the file it describes for simplicity.

docs/news.xml

@@ -17,7 +17,7 @@
 
      Lines should be kept under 80 columns, and should not exceed 100 columns.
 
-     This file is validated against docs/schemas/news.rng schema.
+     This file is validated against docs/news.rng schema.
 
      Use the following template to add a new release section:
 

tests/virschematest.c

@@ -236,7 +236,7 @@ mymain(void)
     DO_TEST_DIR("storagevol.rng", "storagevolxml2xmlin", "storagevolxml2xmlout",
                 "storagevolschemadata");
 
-    DO_TEST_FILE("news.rng", "../docs/news.xml");
+    DO_TEST_FILE("../news.rng", "../docs/news.xml");
 
     return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
 }