JBD2/Ext4: Convert kmalloc to kzalloc in jbd2/ext4

Convert kmalloc to kzalloc() and get rid of the memset().

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index a5fb70f..b1fcf2b 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -96,13 +96,12 @@
 
 alloc_transaction:
 	if (!journal->j_running_transaction) {
-		new_transaction = kmalloc(sizeof(*new_transaction),
+		new_transaction = kzalloc(sizeof(*new_transaction),
 						GFP_NOFS|__GFP_NOFAIL);
 		if (!new_transaction) {
 			ret = -ENOMEM;
 			goto out;
 		}
-		memset(new_transaction, 0, sizeof(*new_transaction));
 	}
 
 	jbd_debug(3, "New handle %p going live.\n", handle);