staging:rtl8192u: Rename CountryIeLen > country_ie_len - Style

Rename CountryIeLen to country_ie_len, coding style change to clear
checkpatch issue with CamelCase naming. The change 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>