Use poll() instead of select()

Since select() has a limit of FD_SETSIZE (typically 1024 on Linux
systems) for the highest fd number it will accept, switch to poll()
instead to avoid these problems when the app Conscrypt is running under
is opening a large amount of file descriptors.

Bug: 25390062
Change-Id: Id54a9cc9379e8db8facd2136e84e9e6fd1f5b0f9
1 file changed