Staging: r8188eu: core: rtw_xmit: Fixed a brace coding style issue

Removed superfluous brackets around a if clause as per checkpatch.pl

Signed-off-by: Chang Yu <marcus.yu.56@gmail.com>
Link: https://lore.kernel.org/r/ff6f2ecb22c3d295ceae0dab593bedfc6eac9e32.1655666628.git.marcus.yu.56@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>