b43: fix build error if !CONFIG_B43_LEDS

Fix the following build error when CONFIG_B43_LEDS is not selected:

drivers/net/wireless/b43/main.c: In function 'b43_remove':
drivers/net/wireless/b43/main.c:4990: error: 'struct b43_leds' has no member named 'stop'
drivers/net/wireless/b43/main.c:4991: error: 'struct b43_leds' has no member named 'work'
make[4]: *** [drivers/net/wireless/b43/main.o] Error 1

Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/leds.h b/drivers/net/wireless/b43/leds.h
index 49d3da5..9592e4c 100644
--- a/drivers/net/wireless/b43/leds.h
+++ b/drivers/net/wireless/b43/leds.h
@@ -63,6 +63,7 @@
 void b43_leds_unregister(struct b43_wldev *dev);
 void b43_leds_init(struct b43_wldev *dev);
 void b43_leds_exit(struct b43_wldev *dev);
+void b43_leds_stop(struct b43_wldev *dev);
 
 
 #else /* CONFIG_B43_LEDS */
@@ -84,6 +85,9 @@
 static inline void b43_leds_exit(struct b43_wldev *dev)
 {
 }
+static inline void b43_leds_stop(struct b43_wldev *dev)
+{
+}
 #endif /* CONFIG_B43_LEDS */
 
 #endif /* B43_LEDS_H_ */