staging: rtl8192ee: Fix setting highest n rate

Commit 4fb6a37c by Andrey Utkin
<andrey.krieger.utkin@gmail.com> and entitled "staging: rtl8192ee:
"Correct bitmask in comparsion" fixed what appeared to be a typo. After
consultation with the Realtek engineers, merely testing for a 2T2R device
is sufficient to ensure that the TX MCS map will equal 0x0c, thus the second
test can be ignored.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>