Fixed StatFs bug occuring on some devices.

Fixes IllegalArgumentException occurring on some devices.

```java.lang.IllegalArgumentException
at android.os.StatFs.native_setup(Native Method)
at android.os.StatFs.(StatFs.java:32)
at com.squareup.picasso.Utils.int calculateDiskCacheSize(java.io.File)(Unknown Source)```
Fixed identation

Made two spaces instead of tabs
Made spaces before ```{``` and ```}```
Small fixes in identation

* Added spaces before size local variable
* Added space before catch
Merge pull request #124 from kkocel/patch-1

Fixed StatFs bug occurring on some devices.