staging: gasket: core: remove kobj_name param from gasket_alloc_dev

gasket_alloc_dev can retrieve the device name from the parent parameter,
a separate parameter isn't needed for this.  Rename the variable to
better reflect its meaning, as the name of the parent device for which a
gasket device is being allocated.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>