Use (std) bool instead of custom bool types

OAI is riddled with boolean_t, FALSE, TRUE, etc. This makes no sense, as
there is a standard bool type, and could lead to nasty bugs if a
definition of a bool is non-standard (0 == false, true == !false). This
commit removes all non-standard bools in the whole project.

openair3/NAS/COMMON/UTIL/socket.c

@@ -397,7 +397,7 @@ static int _socket_set_option(int sfd)
    * and it will simply open another socket on the same port and
    * continue listening.
    */
-  optval = TRUE;
+  optval = true;
 
   if (setsockopt (sfd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval)) < 0) {
     return RETURNerror;
@@ -405,12 +405,12 @@ static int _socket_set_option(int sfd)
 
   /* IPV6_V6ONLY socket option
    * -------------------------
-   * When option is set to TRUE, the socket is restricted to sending and
+   * When option is set to true, the socket is restricted to sending and
    * receiving IPv6 packets only.
-   * When option is set to FALSE, the socket can be used to send and receive
+   * When option is set to false, the socket can be used to send and receive
    * packets to and from an IPv6 address or an IPv4-mapped IPv6 address.
    */
-  optval = FALSE;
+  optval = false;
 
   if (setsockopt (sfd, IPPROTO_IPV6, IPV6_V6ONLY, &optval, sizeof(optval)) < 0) {
     return RETURNerror;