staging: rtl8723bs: remove defined but not used 'dB_Invert_Table'

Fix the following gcc warning:

drivers/staging/rtl8723bs/hal/odm.c:10:18: warning: ‘dB_Invert_Table’
defined but not used [-Wunused-const-variable=]
 static const u16 dB_Invert_Table[8][12] = {
                  ^~~~~~~~~~~~~~~

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200417073439.41888-1-yanaijie@huawei.com


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