hush: fix a signedness bug

Testcase:

set -- a ""; space=" "; printf "<%s>\n" "$@"$space

Before:
<a >
After:
<a>
<>

It usually does not bite since bbox forces -funsigned-char build.

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