ash: eval: Use the correct expansion mode for fd redirection

ash: eval: Use the correct expansion mode for fd redirection

Upstream comment:

    Date: Mon, 19 Nov 2018 18:00:32 +0800
    eval: Use the correct expansion mode for fd redirection

    It has been reported that

            echo test >&$EMPTY_VARIABLE

    causes dash to segfault.  This is a symptom of the bigger problem
    that dash tries to perform pathname expansion as well as field
    splitting on the word after >& and <&.  This is wrong and this
    patch fixes it to use the same expansions as done on a normal
    redirection.

    Reported-by: Andrej Shadura <andrew.shadura@collabora.co.uk>
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>