[nacl] Fix ~NaClProcessHost exit-code reporting.

Correct the process-is-valid check in NaClProcessHost teardown, which
was inverted.

Bug: 1075546
Change-Id: I15df7b084f394d1b50f6300390a6ad0e9e9044dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2165742
Auto-Submit: Wez <wez@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762865}

components/nacl/browser/nacl_process_host.cc

@@ -253,7 +253,7 @@ NaClProcessHost::NaClProcessHost(
 
 NaClProcessHost::~NaClProcessHost() {
   // Report exit status only if the process was successfully started.
-  if (!process_->GetData().GetProcess().IsValid()) {
+  if (process_->GetData().GetProcess().IsValid()) {
     content::ChildProcessTerminationInfo info =
         process_->GetTerminationInfo(false /* known_dead */);
     std::string message =