[PATCH] b43legacy: Fix potential return of uninitialized variable

Using the Coverity checker, Adrian Bunk found that routine b43legacy_start
could return an unitialized variable. This patch fixes the problem.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>