runtime: error formatting fix

g.m is an muintptr, but we want to print it in hex like a pointer.

Change-Id: Ifc48ed77fb2e93cff7a49d98adc7b9679d26c3b1
Reviewed-on: https://go-review.googlesource.com/c/go/+/172988
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/runtime/proc.go

@@ -4124,7 +4124,7 @@ func releasep() *p {
 	}
 	_p_ := _g_.m.p.ptr()
 	if _p_.m.ptr() != _g_.m || _p_.mcache != _g_.m.mcache || _p_.status != _Prunning {
-		print("releasep: m=", _g_.m, " m->p=", _g_.m.p.ptr(), " p->m=", _p_.m, " m->mcache=", _g_.m.mcache, " p->mcache=", _p_.mcache, " p->status=", _p_.status, "\n")
+		print("releasep: m=", _g_.m, " m->p=", _g_.m.p.ptr(), " p->m=", hex(_p_.m), " m->mcache=", _g_.m.mcache, " p->mcache=", _p_.mcache, " p->status=", _p_.status, "\n")
 		throw("releasep: invalid p state")
 	}
 	if trace.enabled {