Fix --with-sysroot in binutils (again)

--with-sysroot removal is insufficient.

There is bad behaviour somewhere that causes --with-sysroot=no as the
default, and then sysroot to be set to 'no'. In reality, we should have
literally no sysroot; so set --with-sysroot=

sysc/binutils-2.38/binutils-2.38.sh

@@ -76,6 +76,7 @@ src_configure() {
             --program-prefix="" \
             --prefix="${PREFIX}" \
             --libdir="${LIBDIR}" \
+            --with-sysroot= \
             --srcdir=.
         cd ..
     done