mei: remove dev_err message on an unsupported ioctl

Currently the driver spams the kernel log on unsupported ioctls which is
unnecessary as the ioctl returns -ENOIOCTLCMD to indicate this anyway.
I suspect this was originally for debugging purposes but it really is not
required so remove it.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/main.c

@@ -528,7 +528,6 @@ static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 		break;
 
 	default:
-		dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd);
 		rets = -ENOIOCTLCMD;
 	}