Revert "imports: wait for fastWalk workers to finish before returning"
Revert "imports: wait for fastWalk workers to finish before returning"

This reverts commit 4436e5475416d77a9352558d118d0b585b962ef1.

Reason for revert: Breaks goimports. See:
https://github.com/golang/go/issues/16399#issuecomment-293248363

Change-Id: I3bda8f0fd32380d19d7daecf3489a24e51abfbe7
Reviewed-on: https://go-review.googlesource.com/40296
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

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