net/ieee80211: ieee80211_is_* can be boolean
net/ieee80211: ieee80211_is_* can be boolean

This patch makes ieee80211_is_* return bool to improve
readability due to these particular functions only using either
one or zero as their return value.

No functional change.

Signed-off-by: Yaowei Bai <d469e57429c50a2c14d8f9c62453b78f8cea7872@163.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs