ext4: use kzalloc in ext4_kzalloc()

Commit 9933fc0i (ext4: introduce ext4_kvmalloc(), ext4_kzalloc(), and
ext4_kvfree()) intruduced wrappers around k*alloc/vmalloc but introduced
a typo for ext4_kzalloc() by not using kzalloc() but kmalloc().

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index e2d88ba..4687fea 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -124,7 +124,7 @@
 {
 	void *ret;
 
-	ret = kmalloc(size, flags);
+	ret = kzalloc(size, flags);
 	if (!ret)
 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 	return ret;