[PATCH] zd1211rw: cleanups

Add static to 2 internal functions. Thanks goes to Adrian Bunk, who found that.

Also made some modifications to the clear functions:

After a discussion on the mailing list, I implemented this code to
have on the one hand sufficient test in debug mode, but on the
other hand reduce the overhead for structure clearing to a
minimum.

A new macro ZD_MEMCLEAR is introduced, which produces code if
DEBUG is set. Locks are not set anymore for structure clearing,
but in debug mode, there is a verification, that the locks have
not been set.

Finally, removed a misleading comment regarding locking in the disconnect
path.

Signed-off-by: Ulrich Kunitz <kune@deine-taler.de>
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/zd1211rw/zd_chip.c

@@ -42,12 +42,11 @@ void zd_chip_init(struct zd_chip *chip,
 
 void zd_chip_clear(struct zd_chip *chip)
 {
-	mutex_lock(&chip->mutex);
+	ZD_ASSERT(!mutex_is_locked(&chip->mutex));
 	zd_usb_clear(&chip->usb);
 	zd_rf_clear(&chip->rf);
-	mutex_unlock(&chip->mutex);
 	mutex_destroy(&chip->mutex);
-	memset(chip, 0, sizeof(*chip));
+	ZD_MEMCLEAR(chip, sizeof(*chip));
 }
 
 static int scnprint_mac_oui(const u8 *addr, char *buffer, size_t size)