init: Initialize uuid pointer

dm_ioctl_export function checks if uuid is NULL if not uses it to extract
uuid cell information and could result to accessing uninitialized pointer.

Change-Id: I88304b157efe03a1ed6eee0eaf04bfe0953646e5
Signed-off-by: Channagoud Kadabi <ckadabi@codeaurora.org>

init/do_mounts_dm.c

@@ -349,7 +349,7 @@ static void __init dm_setup_drives(void)
 	struct dm_table *table = NULL;
 	struct dm_setup_target *target;
 	struct dm_device *dev;
-	char *uuid;
+	char *uuid = NULL;
 	fmode_t fmode = FMODE_READ;
 	struct dm_device *devices;