staging: r8188eu: remove in_cta_test member of struct adapter

bNotifyChannelChange does not changed after initialization.
"if" branches with in_cta_test != 0 removed too.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>