staging: rtl8723bs: remove set but not used variables 'prspbuf' and 'auth'

staging: rtl8723bs: remove set but not used variables 'prspbuf' and 'auth'

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

drivers/staging/rtl8723bs/core/rtw_cmd.c: In function rtw_cmd_thread:
drivers/staging/rtl8723bs/core/rtw_cmd.c:405:16: warning: variable prspbuf set but not used [-Wunused-but-set-variable]
drivers/staging/rtl8723bs/core/rtw_cmd.c: In function rtw_joinbss_cmd:
drivers/staging/rtl8723bs/core/rtw_cmd.c:771:6: warning: variable auth set but not used [-Wunused-but-set-variable]

They are never used, so can be removed.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20190731135953.16784-1-yuehaibing@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>