mlx5: Return -EFAULT instead of -EPERM

For copy_to/from_user() failure, the correct error code is -EFAULT not
-EPERM.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/mlx5/mr.c

@@ -171,7 +171,7 @@ static ssize_t size_write(struct file *filp, const char __user *buf,
 	int c;
 
 	if (copy_from_user(lbuf, buf, sizeof(lbuf)))
-		return -EPERM;
+		return -EFAULT;
 
 	c = order2idx(dev, ent->order);
 	lbuf[sizeof(lbuf) - 1] = 0;
@@ -208,7 +208,7 @@ static ssize_t size_read(struct file *filp, char __user *buf, size_t count,
 		return err;
 
 	if (copy_to_user(buf, lbuf, err))
-		return -EPERM;
+		return -EFAULT;
 
 	*pos += err;
 
@@ -233,7 +233,7 @@ static ssize_t limit_write(struct file *filp, const char __user *buf,
 	int c;
 
 	if (copy_from_user(lbuf, buf, sizeof(lbuf)))
-		return -EPERM;
+		return -EFAULT;
 
 	c = order2idx(dev, ent->order);
 	lbuf[sizeof(lbuf) - 1] = 0;
@@ -270,7 +270,7 @@ static ssize_t limit_read(struct file *filp, char __user *buf, size_t count,
 		return err;
 
 	if (copy_to_user(buf, lbuf, err))
-		return -EPERM;
+		return -EFAULT;
 
 	*pos += err;