b43: only reload config after successful initialization

Commit 2a190322 (b43: reload phy and bss settings after core restarts)
introduced an unconditional call to b43_op_config() at the end of
b43_op_start(). When firmware fails to load this can wedge the system.
There's no need to reload the configuration after a failed
initialization anyway, so only make the call if initialization was
successful.

BugLink: http://bugs.launchpad.net/bugs/950295
Cc: Felix Fietkau <nbd@openwrt.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/b43/main.c

@@ -4827,7 +4827,13 @@ static int b43_op_start(struct ieee80211_hw *hw)
  out_mutex_unlock:
 	mutex_unlock(&wl->mutex);
 
-	/* reload configuration */
+	/*
+	 * Configuration may have been overwritten during initialization.
+	 * Reload the configuration, but only if initialization was
+	 * successful. Reloading the configuration after a failed init
+	 * may hang the system.
+	 */
+	if (!err)
 		b43_op_config(hw, ~0);
 
 	return err;