If the new-name matches the original name, just use the original package.
This avoids situations where there are several packages matching the name and
the behaviour will be inconsistent, occasionally picking different packages.
Since there are multiple glibc packages currently, I'm seeing this behaviour
with cl-posix-mqueue and ecl-cl-posix-mqueue, occasionally they'll use the
hurd glibc variant.
* guix/build-system/asdf.scm (package-with-build-system): Use the original
input packages unless the new-name differs.
Change-Id: I08a1f3ad1290689b5497d31950ada4dc0bfa3a3a
Christopher Baines
15615db61b