[9.20] fix: test: Add missing fclose() when applying updates failed (rpz/testlib)

In rpz system tests, we could leak file if the applying the updates has
failed.  Add the missing fclose() before returning.

Backport of MR !9317

Merge branch 'backport-ondrej/add-missing-flose-to-rpz-testlib-9.20' into 'bind-9.20'

See merge request isc-projects/bind9!9345

bin/tests/system/rpz/testlib/test-data.c

@@ -1352,6 +1352,7 @@ load_all_updates(const char *fname, trpz_result_t **presults, size_t *pnresults,
 		{
 			fprintf(stderr,
 				"Error: could not apply update \"%s\"\n", lptr);
+			fclose(f);
 			return (-1);
 		}
 	}