jffs2: Use kzalloc instead of kmalloc/memset

Use kzalloc rather than duplicating its implementation, which
makes code simple and easy to understand.

Signed-off-by: Haowen Bai <[e-mail]>
[rw: Fixed printk string]
Signed-off-by: Richard Weinberger <[e-mail]>

fs/jffs2/erase.c

···
 	jffs2_dbg(1, "%s(): erase block %#08x (range %#08x-%#08x)\n",
 		  __func__,
 		  jeb->offset, jeb->offset, jeb->offset + c->sector_size);
-	instr = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
+	instr = kzalloc(sizeof(struct erase_info), GFP_KERNEL);
 	if (!instr) {
-		pr_warn("kmalloc for struct erase_info in jffs2_erase_block failed. Refiling block for later\n");
+		pr_warn("kzalloc for struct erase_info in jffs2_erase_block failed. Refiling block for later\n");
 		mutex_lock(&c->erase_free_sem);
 		spin_lock(&c->erase_completion_lock);
 		list_move(&jeb->list, &c->erase_pending_list);
···
 		mutex_unlock(&c->erase_free_sem);
 		return;
 	}
-
-	memset(instr, 0, sizeof(*instr));
 
 	instr->addr = jeb->offset;
 	instr->len = c->sector_size;