veyron2/vdl: remove canonicalPath hack
veyron2/vdl: remove canonicalPath hack

it's not required to generate types in vdlroot/src correctly
and behaves wrong for java and javascript

Change-Id: I57e2515ef5a9ea9492ad15a47d42222b2647ff42

vanadium/go.v23,vanadium/go.v23,vanadium/go.v23