Make parallel_emerge logs readable by all.

Python does not support creating temporary files that are readable by
all, so we need to chmod the file to make it readable.

BUG=chromium-os:31194
TEST=Run example merge. Verify the logs are readable by all now.

Change-Id: Ibe16838d01f5c9aacb487ab154c8028e0f3666e6
Reviewed-on: https://gerrit.chromium.org/gerrit/24831
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: David James <davidjames@chromium.org>
Tested-by: David James <davidjames@chromium.org>
diff --git a/scripts/parallel_emerge.py b/scripts/parallel_emerge.py
index 31865d7..4b80208 100644
--- a/scripts/parallel_emerge.py
+++ b/scripts/parallel_emerge.py
@@ -956,6 +956,7 @@
     install_list = [db_pkg]
     pkgname = db_pkg.pf
     output = tempfile.NamedTemporaryFile(prefix=pkgname + "-", delete=False)
+    os.chmod(output.name, 644)
     start_timestamp = time.time()
     job = EmergeJobState(target, pkgname, False, output.name, start_timestamp,
                          fetch_only=fetch_only)