Bug in multi_socket_bases get_direct_mem_ptr

[zeiadzaf]

systemC version: SystemC231
File Name : tlm_utils/multi_socket_bases.h
Function Name : get_direct_mem_ptr

Issue description:
If m_dmi_f is set (!= 0) but empty (m_dmi_f->empty() returns true), calls to get_direct_mem_ptr function will cause simulation crash.
The condition if ((m_dmi_f == 0) && (m_dmi_f && m_dmi_f->empty())) { does not make sense.

Proposed fix: if ((m_dmi_f == 0) || (m_dmi_f && m_dmi_f->empty())) {

Thanks