linux-wandboard

b43: update flushing many writes performed in a row

Flush radio writes as well and add some tiny optimizations (e.g.
masksetting PHY reg involves reading it, so reset the counter).

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>