b43legacy: properly fix a bogus gcc warning

Use initialized_var() to properly fix a bogus gcc warning.

Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Cc: Frank Lichtenheld <frank@lichtenheld.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43legacy/debugfs.c b/drivers/net/wireless/b43legacy/debugfs.c
index 619b453..03ce082 100644
--- a/drivers/net/wireless/b43legacy/debugfs.c
+++ b/drivers/net/wireless/b43legacy/debugfs.c
@@ -209,7 +209,7 @@
 	struct b43legacy_wldev *dev;
 	struct b43legacy_debugfs_fops *dfops;
 	struct b43legacy_dfs_file *dfile;
-	ssize_t ret = 0;
+	ssize_t uninitialized_var(ret);
 	char *buf;
 	const size_t bufsize = 1024 * 128;
 	const size_t buforder = get_order(bufsize);