staging: rtl8188eu: remove unused argument

The function rtw_os_recv_resource_alloc() only uses the argument
struct recv_frame *. So remove the other unused argument.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>