ash: expand: Fix bugs with words connected to the right of $@

ash: expand: Fix bugs with words connected to the right of $@

Upstream email:

    This is actually composed of two bugs.  First of all our tracking
    of quotemark is wrong so anything after "$@" becomes quoted.  Once
    we fix that then the problem is that the first space character
    after "$@" is not recognised as an IFS.

    This patch fixes both.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>