on subsequent calls. Newterm() would fail after a few calls, leading to vi
exiting with a "ex/vi: error initializing terminal" message
. if tcsetattr() fails due to EINTR, ignore it
Fixes PR #25849
error message when TERM is not set. This might or might not be a
reasonable permanent fix -- I'm waiting to hear back from Keith Bostic.
Problem was reported in pr-3816 by Erik Fair.