Properly pass :element-type to with-output-to-string
This should fix bug #1855911 as reported by Martin Simmons, with a change based on a patch submitted by Martin: https://bugs.launchpad.net/asdf/+bug/1855911
This should fix bug #1855911 as reported by Martin Simmons, with a change based on a patch submitted by Martin: https://bugs.launchpad.net/asdf/+bug/1855911