cmd/guru: emacs: Use cl-lib.el instead of cl.el
cmd/guru: emacs: Use cl-lib.el instead of cl.el

This package requires cl-lib.el in package header but it is not loaded
and cl.el functions are used instead of cl-lib functions. Using cl.el
functions causes byte-compile warnings.

Change-Id: I6d9400f9ced6a5cc0592d83da2ab1c1cf34e20b8
Reviewed-on: https://go-review.googlesource.com/27031
Reviewed-by: Alan Donovan <7069e9552f9d110b0a0f326b96f22f63fb99dfc1@google.com>

golang/tools,golang/tools,syreclabs/go-tools,syreclabs/go-tools,syreclabs/go-tools,syreclabs/go-tools,golang/tools,golang/tools,golang/tools,syreclabs/go-tools,syreclabs/go-tools