staging:rtl8192u: Remove unused page-a Bit Mask definitions - Style

Remove the unused 'page-a' Bit Mask definitions. These definitions will
fail the checkpatch CamelCase naming tests, rather then renaming, as the
definitions are unused, they have simply been removed.

This is a coding style change and should have no impact on runtime
code execution.

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