Do not clear LLCP listen callback when an incoming socket is detected.

This would prohibit detection of multiple incoming socket in a row.

Change-Id: I9e3907a92b706de2da7642ccd92668b9868d1996
diff --git a/src/phFriNfc_LlcpTransport_Connection.c b/src/phFriNfc_LlcpTransport_Connection.c
index b169ea3..4b89bbb 100644
--- a/src/phFriNfc_LlcpTransport_Connection.c
+++ b/src/phFriNfc_LlcpTransport_Connection.c
@@ -728,7 +728,6 @@
                /* Get the ListenCB of the socket */
                pListen_Cb = psLocalLlcpSocket->pfSocketListen_Cb;
                pListenContext = psLocalLlcpSocket->pListenContext;
-               psLocalLlcpSocket->pfSocketListen_Cb = NULL;
                break;
             }
          }
@@ -749,7 +748,6 @@
               /* Get the Listen CB and the Context of the socket */
                pListen_Cb = psLocalLlcpSocket->pfSocketListen_Cb;
                pListenContext = psLocalLlcpSocket->pListenContext;
-               psLocalLlcpSocket->pfSocketListen_Cb = NULL;
               break;
            }
         }