staging: rtl8192e: Remove set but not used variables 'broad_addr, stype'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/staging/rtl8192e/rtl8192e/rtl_core.c: In function '_rtl92e_tx':
drivers/staging/rtl8192e/rtl8192e/rtl_core.c:1732:28: warning:
 variable 'broad_addr' set but not used [-Wunused-but-set-variable]

drivers/staging/rtl8192e/rtl8192e/rtl_core.c:1731:24: warning:
 variable 'stype' set but not used [-Wunused-but-set-variable]

This remove unnessesary bool variable 'multi_addr, broad_addr, uni_addr'
Also 'stype' never used and  can be removed.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>