staging:rtl8192u: remove typedef from structure SwChnlCmd - Style

Checkpatch warns against creation of new types in code. This patch simply
removes the "typedef" declaration of the structure SwChnlCmd to clear this
issue. Simple coding style issue which should not impact runtime execution.

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