Updated git submodules

Project: releng/builder master 5a42f4d1caae5ab66d72559d39fbaa7da21e9c64

Merge "Make packer jobs build sequentially"

Make packer jobs build sequentially

This unclutters the console logs and makes it easier to
read/parse the logs.

Change-Id: Ia8043efec15081af476de4721ffd9eb9c47d2889
Signed-off-by: Anil Belur <abelur@linuxfoundation.org>

diff --git a/docs/submodules/releng/builder b/docs/submodules/releng/builder
index 1587cfac1c9d8b9a6c3e27cb3def617d8049f30c..5a42f4d1caae5ab66d72559d39fbaa7da21e9c64 160000 (submodule)
--- a/docs/submodules/releng/builder
+++ b/docs/submodules/releng/builder
@@ -1 +1 @@
-Subproject commit 1587cfac1c9d8b9a6c3e27cb3def617d8049f30c
+Subproject commit 5a42f4d1caae5ab66d72559d39fbaa7da21e9c64