ubifs: Use kmalloc_array()

Since commit 6da2ec56 ("treewide: kmalloc() -> kmalloc_array()")
we use kmalloc_array() for kmalloc() that computes the length with
a multiplication.

Cc: Kees Cook <keescook@chromium.org>
Suggested-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NRichard Weinberger <richard@nod.at>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NRichard Weinberger <richard@nod.at>

fs/ubifs/journal.c

@@ -1291,7 +1291,7 @@ static int truncate_data_node(const struct ubifs_info *c, const struct inode *in
 	int err, dlen, compr_type, out_len, old_dlen;
 
 	out_len = le32_to_cpu(dn->size);
-	buf = kmalloc(out_len * WORST_COMPR_FACTOR, GFP_NOFS);
+	buf = kmalloc_array(out_len, WORST_COMPR_FACTOR, GFP_NOFS);
 	if (!buf)
 		return -ENOMEM;