cmd/internal/obj: rip out argp adjustment for wrapper frames

cmd/internal/obj: rip out argp adjustment for wrapper frames

The previous CL made this adjustment unnecessary. The argp field
is no longer used by the runtime.

Change-Id: I3491eeef4103c6653ec345d604c0acd290af9e8f
Reviewed-on: https://go-review.googlesource.com/c/go/+/685356
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>