When debugging you want to be lazy and not have to parse
bits yourself so let mac80211 debugfs do the parsing for you.

This is what I get against my WRT610N:

root@tux:~# cat /sys/kernel/debug/ieee80211/phy0/stations/00\:22\:6b\:aa\:bb\:01/ht_capa
ht supported
cap: 0x000e
	HT20/HT40
	SM Power Save disabled
	No RX STBC
	Max AMSDU length: 7935 bytes
	No DSSS/CCK HT40
ampdu factor/density: 2/6
MCS mask: ff ff 00 00 00 00 00 00 00 00
MCS rx highest: 0
MCS tx params: 0

Cc: johannes@sipsolutions.net
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>