cmd/vet: remove copylock warning about result types and calls
Don't issue a copylock warning about a result type; the function may
return a composite literal with a zero value, which is OK.
Don't issue a copylock warning about a function call on the RHS, or an
indirection of a function call; the function may return a composite
literal with a zero value, which is OK.
Updates #16227.
Change-Id: I94f0e066bbfbca5d4f8ba96106210083e36694a2
Reviewed-on: https://go-review.googlesource.com/24711 Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Rob Pike <r@golang.org>