CIFS: Decrease verbosity of ioctl call

Cc: Stable <stable@vger.kernel.org> # v4.9+
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>