mwifiex: copy AP's HT capability info correctly

commit c99b1861c232e1f641f13b8645e0febb3712cc71 upstream.

While preparing association request, intersection of device's HT
capability information and corresponding fields advertised by AP
is used.

This patch fixes an error while copying this field from AP's
beacon.

Change-Id: I43bc47553f1ee28de0e1898777c6b21298efd254
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>