Update git submodules

* Update docs/submodules/releng from branch 'master'
  - [Yardstick] add apt-get autoremove to free up disk space
    
    yardstick builds are failing due to running out of disk space
    when too many kernels are left installed.
    
    Try apt-get autoremove to cleanup before updating
    
    [yardstick-verify-master] $ /bin/bash /tmp/jenkins4572301318127685434.sh
    Reading package lists...
    Building dependency tree...
    Reading state information...
    build-essential is already the newest version (12.1ubuntu2).
    python3-dev is already the newest version (3.5.1-3).
    python-dev is already the newest version (2.7.12-1~16.04).
    The following packages were automatically installed and are no longer required:
      linux-headers-4.4.0-101 linux-headers-4.4.0-101-generic
      linux-headers-4.4.0-103 linux-headers-4.4.0-103-generic
      linux-headers-4.4.0-104 linux-headers-4.4.0-104-generic
      linux-headers-4.4.0-108 linux-headers-4.4.0-108-generic
      linux-headers-4.4.0-109 linux-headers-4.4.0-109-generic
      linux-image-4.4.0-101-generic linux-image-4.4.0-103-generic
      linux-image-4.4.0-104-generic linux-image-4.4.0-108-generic
      linux-image-4.4.0-109-generic linux-image-extra-4.4.0-101-generic
      linux-image-extra-4.4.0-103-generic linux-image-extra-4.4.0-104-generic
      linux-image-extra-4.4.0-108-generic linux-image-extra-4.4.0-109-generic
    Use 'sudo apt autoremove' to remove them.
    0 upgraded, 0 newly installed, 0 to remove and 111 not upgraded.
    4 not fully installed or removed.
    After this operation, 0 B of additional disk space will be used.
    Setting up linux-image-extra-4.4.0-116-generic (4.4.0-116.140) ...
    run-parts: executing /etc/kernel/postinst.d/apt-auto-removal 4.4.0-116-generic /boot/vmlinuz-4.4.0-116-generic
    run-parts: executing /etc/kernel/postinst.d/dkms 4.4.0-116-generic /boot/vmlinuz-4.4.0-116-generic
    run-parts: executing /etc/kernel/postinst.d/initramfs-tools 4.4.0-116-generic /boot/vmlinuz-4.4.0-116-generic
    update-initramfs: Generating /boot/initrd.img-4.4.0-116-generic
    W: mdadm: /etc/mdadm/mdadm.conf defines no arrays.
    
    gzip: stdout: No space left on device
    E: mkinitramfs failure cpio 141 gzip 1
    update-initramfs: failed for /boot/initrd.img-4.4.0-116-generic with 1.
    
    Change-Id: I79396162c5300c8cbaecc474473af81842f79db8
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>
    

1 files changed, 0 insertions, 0 deletions

diff --git a/docs/submodules/releng b/docs/submodules/releng
-Subproject dab620d71a1d2c36d89957038b22c37a4ff2420
+Subproject 40726f62ad2bf46cd1100438002dbb66bd7a2dc