Revert 281831 "Fix nacl_integration to run 32bit tests with 32bi..."

> Fix nacl_integration to run 32bit tests with 32bit userland and 64bit kernel.
> 
> detect_host_arch.py already knows how to figure this out, so reuse it.
> (It could probably be used in the darwin and maybe even in the windows
> branch too.)
> 
> BUG=368384
> TEST=nacl_integration on http://build.chromium.org/p/chromium.linux/builders/Linux%20Tests%20%28dbg%29%282%29%2832%29/ goes green
> TBR=mseaborn@chromium.org
> 
> Review URL: https://codereview.chromium.org/373253002

Suspect this is causing the failure http://build.chromium.org/p/chromium.win/builders/NaCl%20Tests%20%28x86-64%29/builds/13394

TBR=thakis@chromium.org

Review URL: https://codereview.chromium.org/374383002

git-svn-id: http://src.chromium.org/svn/trunk/src/build@281999 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

detect_host_arch.py

@@ -10,8 +10,13 @@ import re
 import sys
 
 
-def HostArch():
-  """Returns the host architecture with a predictable string."""
+def main():
+  print DoMain([])
+  return 0
+
+def DoMain(_):
+  """Hook to be called from gyp without starting a separate python
+  interpreter."""
   host_arch = platform.machine()
 
   # Convert machine type to format recognized by gyp.
@@ -31,10 +36,5 @@ def HostArch():
 
   return host_arch
 
-def DoMain(_):
-  """Hook to be called from gyp without starting a separate python
-  interpreter."""
-  return HostArch()
-
 if __name__ == '__main__':
-  print DoMain([])
+  sys.exit(main())