[release-branch.go1.11] cmd/link: increase the function call limit in stkcheck

There is real (albeit generated) code that exceeds the limit.

Updates #33555
Fixes #33556

Change-Id: I668e85825d3d2a471970e869abe63f3492213cc1
Reviewed-on: https://go-review.googlesource.com/c/go/+/189697


Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
(cherry picked from commit 951143cf)
Reviewed-on: https://go-review.googlesource.com/c/go/+/189737