Removed call to TryCreateDirectory from GetDefaultDataDir in src/util.cpp.

See https://github.com/bitcoin/bitcoin/issues/7845#issuecomment-207684728.
Also refactored `GetDefaultDataDir` function to return path for Mac in one expression.

src/util.cpp

@@ -471,9 +471,7 @@ boost::filesystem::path GetDefaultDataDir()
         pathRet = fs::path(pszHome);
 #ifdef MAC_OSX
     // Mac
-    pathRet /= "Library/Application Support";
+    return pathRet / "Library/Application Support/Bitcoin";
-    TryCreateDirectory(pathRet);
-    return pathRet / "Bitcoin";
 #else
     // Unix
     return pathRet / ".bitcoin";