Make the path and path2 attributes equivalent. Remove some uses

src/test/run-pass/mod_dir_path.rs

@@ -12,7 +12,7 @@
 // xfail-fast
 
 mod mod_dir_simple {
-    #[path2 = "test.rs"]
+    #[path = "test.rs"]
     pub mod syrup;
 }