b43: Fix swatch warning

Swatch reports the following warning for main.c:

  CHECK   drivers/net/wireless/b43/main.c
drivers/net/wireless/b43/main.c +4115 b43_wireless_core_stop(7) warn: variable dereferenced before check 'dev'

After analysis, this is not a bug, but a false warning. Nonetheless,
a cleanup is in order to prevent some future janitor proposing
the wrong fix, as I did in my original patch.

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

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index d2b1d1fe202b..172294170df8 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -4131,10 +4131,13 @@ out_unlock:
  * because the core might be gone away while we unlocked the mutex. */
 static struct b43_wldev * b43_wireless_core_stop(struct b43_wldev *dev)
 {
-        struct b43_wl *wl = dev->wl;
+        struct b43_wl *wl;
         struct b43_wldev *orig_dev;
         u32 mask;
 
+        if (!dev)
+                return NULL;
+        wl = dev->wl;
 redo:
         if (!dev || b43_status(dev) < B43_STAT_STARTED)
                 return dev;