Removed duplicate _get_wwn() from PSCSIStorageObject.
Removed duplicate _get_wwn() from PSCSIStorageObject.

* The method was redefined there identically to parent StorageObject's one.

roidayan/rtslib,roidayan/rtslib,agrover/rtslib-fb,mikenawrocki/rtslib-fb,Datera/rtslib,cvubrugier/rtslib-fb,JonnyJD/rtslib-fb,mikenawrocki/rtslib-fb,Datera/rtslib