test: fix nilptr3 check for wasm
test: fix nilptr3 check for wasm

CL 131735 only updated nilptr3.go for the adjusted nil check. Adjust
nilptr3_wasm.go as well.

Change-Id: I4a6257d32bb212666fe768dac53901ea0b051138
Reviewed-on: https://go-review.googlesource.com/133495
Run-TryBot: Tobias Klauser <0a68dd4915066ec5d3f81f75a828fee53dcc8822@gmail.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

nawawi/go,golang/go,nawawi/go,josharian/go,golang/go,cloudflare/go,josharian/go,nawawi/go,golang/go,josharian/go,CAFxX/go,akutz/go,akutz/go,CAFxX/go,golang/go,nawawi/go,cloudflare/go,akutz/go,nawawi/go,golang/go,akutz/go,golang/go,josharian/go,akutz/go,akutz/go,akutz/go,golang/go,CAFxX/go,nawawi/go,cloudflare/go,cloudflare/go,akutz/go,josharian/go,cloudflare/go,CAFxX/go,nawawi/go,CAFxX/go,josharian/go,cloudflare/go,CAFxX/go,nawawi/go,CAFxX/go,cloudflare/go,golang/go,cloudflare/go,josharian/go,CAFxX/go,josharian/go