staging:rtl8192u: Correct spelling in comments - style

Correct the spelling of a number of comments, which cause a checkpatch
issue. This is purely a coding style change which 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>