kernel: Set the initial foreground process group when acquiring a controlling terminal

kernel/src/fs/devices/SlavePTY.cpp

@@ -99,6 +99,7 @@ Result<u64> SlavePTY::ioctl(int request, void* arg)
         });
 
         m_master->m_session = current->sid;
+        m_master->m_foreground_process_group = current->pgid;
 
         return 0;
     }