In set_termios(), interrupts where not disabled if UART_ENABLE_MS() was
false.

Tested on at91sam9g35.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org> # >= 3.16
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>