Improved logging when there's an error creating the directories in getFilesDir()

Improved logging when there's an error creating the
directories in getFilesDir();

Due to mkdirs() only returns false on errors,
it's better to output the directory path so the dev
knows the path that can not be created
See also Issue 8886
http://code.google.com/p/android/issues/detail?id=8886

Change-Id: I44d6adc8508ef9ca57f000b5d7bceeb0cfa3ed13