staging:rtl8192u: Clean cmpk_counttxstatistic() comments - Style

The only useful piece of information in the header comment of this
static function was the name of the function and parameters. That
is not useful information, given that they are in the C Source of
the function declaration, a few lines below the comment. The block
comment has been removed.

This is a coding style change, there should be no impact on runtime
code execution.

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