Fix an uninitialized variable in drivers/net/wireless/b43/main.c::b43_start().

Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: NWANG Cong <xiyou.wangcong@gmail.com>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: "John W. Linville" <linville@tuxdriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>