Without this fix, the function would still end up returning NULL but it
would put that NULL connection in the hash table which would be bad.
Signed-off-by: Jason Ekstrand <jason@jlekstrand.net> Reviewed-by: Dave Airlie <airlied@redhat.com> Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com> Cc: "13.0" <mesa-stable@lists.freedesktop.org>