Staging: rtl8723bs: Remove dead code

"oldmem==NULL;"
The above bug under the ifdef code would have caused a GCC
warning if it were ever compiled. Hence, remove the dead ifdefed
code from the file.

Signed-off-by: Shreeya Patel <shreeya.patel23498@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>