ceph: silence uninitialized variable warning

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index deb51bd..924e6ca 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -808,7 +808,7 @@
 	struct ceph_client *client;
 	int err;
 	int (*compare_super)(struct super_block *, void *) = ceph_compare_super;
-	const char *path;
+	const char *path = 0;
 
 	dout("ceph_get_sb\n");