cmd/oracle: emacs: look for oracle on $PATH and nowhere else
cmd/oracle: emacs: look for oracle on $PATH and nowhere else

Change-Id: Ifbc8e3ff6fe22a56e29fe7ba8004510cb0cee343
Reviewed-on: https://go-review.googlesource.com/9687
Reviewed-by: Dominik Honnef <aeacd46bb4fd3f59504c7762d9af6bd04f20aa1f@honnef.co>
Reviewed-by: David Crawshaw <a2f0bf29257797dd66800b4fbb9945c3e216c004@golang.org>

argandas/tools,matryer/tools,syreclabs/go-tools,syreclabs/go-tools,cw2018/tools,nicot/tools,syreclabs/go-tools,syreclabs/go-tools,nicot/tools,cw2018/tools,glasser/golang-tools,cmars/tools,josharian/tools,sshetty10/tools,jdhenke/tools,nicot/tools,argandas/tools,magiccao/tools,cmars/tools,golang/tools,cmars/tools,syreclabs/go-tools,magiccao/tools,jdhenke/tools,matryer/tools,cw2018/tools,cmars/tools,runcom/tools,sshetty10/tools,glasser/golang-tools,runcom/tools,runcom/tools,cw2018/tools,sshetty10/tools,springning/tools,magiccao/tools,runcom/tools,glasser/golang-tools,argandas/tools,sshetty10/tools,jdhenke/tools,magiccao/tools,syreclabs/go-tools,golang/tools,josharian/tools,glasser/golang-tools,nicot/tools,golang/tools,jdhenke/tools,springning/tools,springning/tools,springning/tools,matryer/tools,golang/tools,josharian/tools,argandas/tools,golang/tools,josharian/tools,matryer/tools