dm table: remove superfluous variable reset

If allocation fails, the local var *t is not used any more after kfree.
Don't need to reset it to NULL. Remove the unnecesary NULL set here.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index daf25d0..c95405d 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -217,7 +217,6 @@
 
 	if (alloc_targets(t, num_targets)) {
 		kfree(t);
-		t = NULL;
 		return -ENOMEM;
 	}