staging:rtl8192u: Remove typedef and rename DOT11D_STATE - Style

Remove typedef from enumerated type DOT11D_STATE to clear checkpatch issue
with declaring new types.

Rename the enumertion from DOT11D_STATE to dot11d_state.

These changes are coding style changes which should not effect runtime
execution of code.

Signed-off-by: John Whitmore <johnfwhitmore@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>