staging:rtl8192u: Rename bEnabled > enabled - Style

Rename the member variable bEnabled to enabled. This change clears the
checkpatch issue with CamelCase. Purely a coding style change which should not
impact runtime execution.

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