ash: let ignoreeof only affect interactive shells

Commit fb7d6c89 from Harald van Dijk's gwsh variant of ash
(https://github.com/hvdijk/gwsh):

    ignoreeof is documented as only having an effect for interactive shells,
    but is implemented as having mostly the same effect for interactive
    shells as for non-interactive shells. Change the implementation to match
    the documentation.

    Test case:

      $SHELL -o ignoreeof /dev/null

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Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
1 file changed