adb: switch the socket list mutex to a recursive_mutex.

sockets.cpp was branching on whether a socket close function was
local_socket_close in order to avoid a potential deadlock if the socket
list lock was held while closing a peer socket.

Bug: http://b/28347842
Change-Id: I5e56f17fa54275284787f0f1dc150d1960256ab3
(cherry picked from commit 9b587dec6d0a57c8fe1083c1c543fbeb163d65fa)

void close_all_sockets(atransport* t) {
    asocket* s;


     /* this is a little gross, but since s->close() *will* modify
     ** the list out from under you, your options are limited.
     */
    std::lock_guard<std::recursive_mutex> lock(local_socket_list_lock);
 restart:
     for (s = local_socket_list.next; s != &local_socket_list; s = s->next) {
         if (s->transport == t || (s->peer && s->peer->transport == t)) {
            local_socket_close(s);
             goto restart;
         }
     }
 }

void close_all_sockets(atransport* t) {
    asocket* s;


     /* this is a little gross, but since s->close() *will* modify
     ** the list out from under you, your options are limited.
     */
    adb_mutex_lock(&socket_list_lock);
 restart:
     for (s = local_socket_list.next; s != &local_socket_list; s = s->next) {
         if (s->transport == t || (s->peer && s->peer->transport == t)) {
            local_socket_close_locked(s);
             goto restart;
         }
     }
    adb_mutex_unlock(&socket_list_lock);
 }
