Staging: wilc1000: coreconfigurator: Remove irrelevant wrapper function

Remove the function get_current_channel() and replace its calls by
get_current_channel_802_11n() as the former function's definition
involves only returning the value of latter function.
Semantic patch used to find out the issue:

@@
identifier f,g;
@@

*f(...) {
 return g(...); }

Signed-off-by: Shivani Bhardwaj <shivanib134@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>