CL 22372 changed ppc64le to use normal cgo initialization on ppc64le.
Doing this uncovered a cmd/link error using internal linking.
Opened issue 15409 for the problem.  This CL disables the test.

Update #15409.

Change-Id: Ia1bb6b874c1b5a4df1a0436c8841c145142c30f7
Reviewed-on: https://go-review.googlesource.com/22379
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>