[CLATJ#29] Remove the throwaway sockets for dup2 fds

Don't need these temporary socket fds anymore because the
posix_spawn_file_actions_adddup2() will clean up the flag
O_CLOEXEC for dup2 fd == new_fd before forking.

Bug: 218407445
Test: connect to ipv6 only network and ping 8.8.8.8
Change-Id: I70b8a03a6a13393a30a8a63599b8d1468347c560
1 file changed