tty: serial: samsung: Remove superfluous braces in macro

tty: serial: samsung: Remove superfluous braces in macro

Commit 59f37b7370ef ("tty: serial: samsung: Remove USI initialization")
removes parameters from EXYNOS_COMMON_SERIAL_DRV_DATA() macro, but
leaves unnecessary empty braces. Remove those to fix the style. No
functional change.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240202010507.22638-1-semen.protsenko@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>