serial: core: Simplify uart_get_rs485_mode()

serial: core: Simplify uart_get_rs485_mode()

[ Upstream commit 7cda0b9eb6eb9e761f452e2ef4e81eca20b19938 ]

Simplify uart_get_rs485_mode() by using temporary variable for
the GPIO descriptor. With that, use proper type for the flags
of the GPIO descriptor.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20231003142346.3072929-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 1a33e33ca0e8 ("serial: core: set missing supported flag for RX during TX GPIO")
Signed-off-by: Sasha Levin <sashal@kernel.org>