net/http/pprof: attach handlers using http.HandleFunc
net/http/pprof: attach handlers using http.HandleFunc

Simplify how pprof attaches the handlers to the DefaultMux by using
http.HandleFunc instead of manually wrapping the handlers in
a http.HandlerFunc.

Change-Id: I65db262ebb2e29e4b6f30df9d2688f5daf782c29
Reviewed-on: https://go-review.googlesource.com/71251
Reviewed-by: Sam Whited <f16bed56189e249fe4ca8ed10a1ecae60e8ceac0@samwhited.com>
Reviewed-by: Tom Bergan <3b77d7da34779f829901a664ac7c87d255b041af@google.com>
Run-TryBot: Sam Whited <f16bed56189e249fe4ca8ed10a1ecae60e8ceac0@samwhited.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

Cofyc/go,CAFxX/go,golang/go,golang/go,nawawi/go,josharian/go,Cofyc/go,Cofyc/go,cloudflare/go,nawawi/go,nawawi/go,Cofyc/go,codestation/go,golang/go,golang/go,CAFxX/go,codestation/go,golang/go,akutz/go,akutz/go,josharian/go,cloudflare/go,golang/go,codestation/go,Cofyc/go,codestation/go,akutz/go,CAFxX/go,nawawi/go,codestation/go,nawawi/go,CAFxX/go,golang/go,josharian/go,Cofyc/go,cloudflare/go,cloudflare/go,nawawi/go,CAFxX/go,Cofyc/go,josharian/go,cloudflare/go,akutz/go,josharian/go,nawawi/go,josharian/go,akutz/go,cloudflare/go,akutz/go,CAFxX/go,akutz/go,cloudflare/go,CAFxX/go,codestation/go,nawawi/go,akutz/go,CAFxX/go,Cofyc/go,cloudflare/go,codestation/go,golang/go,christopher-henderson/Go,josharian/go,josharian/go,codestation/go