Use existing helper function mwifiex_fill_cap_info to fill
the HT CAP info for ibss beacons.

Also removing extra parenthesis block for better readability.
Signed-off-by: NYogesh Ashok Powar <yogeshp@marvell.com>
Signed-off-by: NBing Zhao <bzhao@marvell.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>