staging: rtl8723bs: remove unused code

There are two final hunks of code that are only built
if SDIO_DYNAMIC_ALLOC_MEM is defined however this is never
defined and if it was the code would lead to dereferencing
an uninitialized pointer oldmem.  It appears that a previous
commit 1babeb0c ("Staging: rtl8723bs: Remove dead code")
removed some of the dead code but not all of it. Clean this
up by removing the final hunks.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>