Upgrade containerd to latest version.

Necessary for merging in #22049.

Signed-off-by: Ross Boucher <rboucher@gmail.com>

Dockerfile

@@ -239,7 +239,7 @@ RUN set -x \
 	&& rm -rf "$GOPATH"
 
 # Install containerd
-ENV CONTAINERD_COMMIT 0ac3cd1be170d180b2baed755e8f0da547ceb267
+ENV CONTAINERD_COMMIT 8508d2bec90b96403143a1104cdcbd56f6aeb361
 RUN set -x \
 	&& export GOPATH="$(mktemp -d)" \
 	&& git clone https://github.com/docker/containerd.git "$GOPATH/src/github.com/docker/containerd" \

Dockerfile.aarch64

@@ -195,7 +195,7 @@ RUN set -x \
 	&& rm -rf "$GOPATH"
 
 # Install containerd
-ENV CONTAINERD_COMMIT 0ac3cd1be170d180b2baed755e8f0da547ceb267
+ENV CONTAINERD_COMMIT 8508d2bec90b96403143a1104cdcbd56f6aeb361
 RUN set -x \
 	&& export GOPATH="$(mktemp -d)" \
 	&& git clone https://github.com/docker/containerd.git "$GOPATH/src/github.com/docker/containerd" \

Dockerfile.armhf

@@ -193,7 +193,7 @@ RUN set -x \
 	&& rm -rf "$GOPATH"
 
 # Install containerd
-ENV CONTAINERD_COMMIT 0ac3cd1be170d180b2baed755e8f0da547ceb267
+ENV CONTAINERD_COMMIT 8508d2bec90b96403143a1104cdcbd56f6aeb361
 RUN set -x \
 	&& export GOPATH="$(mktemp -d)" \
 	&& git clone https://github.com/docker/containerd.git "$GOPATH/src/github.com/docker/containerd" \

Dockerfile.ppc64le

@@ -206,7 +206,7 @@ RUN set -x \
 	&& rm -rf "$GOPATH"
 
 # Install containerd
-ENV CONTAINERD_COMMIT 0ac3cd1be170d180b2baed755e8f0da547ceb267
+ENV CONTAINERD_COMMIT 8508d2bec90b96403143a1104cdcbd56f6aeb361
 RUN set -x \
 	&& export GOPATH="$(mktemp -d)" \
 	&& git clone https://github.com/docker/containerd.git "$GOPATH/src/github.com/docker/containerd" \

Dockerfile.s390x

@@ -214,7 +214,7 @@ RUN set -x \
 	&& rm -rf "$GOPATH"
 
 # Install containerd
-ENV CONTAINERD_COMMIT 0ac3cd1be170d180b2baed755e8f0da547ceb267
+ENV CONTAINERD_COMMIT 8508d2bec90b96403143a1104cdcbd56f6aeb361
 RUN set -x \
 	&& export GOPATH="$(mktemp -d)" \
 	&& git clone https://github.com/docker/containerd.git "$GOPATH/src/github.com/docker/containerd" \

Dockerfile.simple

@@ -68,7 +68,7 @@ RUN set -x \
 	&& rm -rf "$GOPATH"
 
 # Install containerd
-ENV CONTAINERD_COMMIT 0ac3cd1be170d180b2baed755e8f0da547ceb267
+ENV CONTAINERD_COMMIT 8508d2bec90b96403143a1104cdcbd56f6aeb361
 RUN set -x \
 	&& export GOPATH="$(mktemp -d)" \
 	&& git clone https://github.com/docker/containerd.git "$GOPATH/src/github.com/docker/containerd" \

hack/vendor.sh

@@ -136,7 +136,7 @@ clone git google.golang.org/cloud dae7e3d993bc3812a2185af60552bb6b847e52a0 https
 clone git github.com/docker/docker-credential-helpers v0.3.0
 
 # containerd
-clone git github.com/docker/containerd 0ac3cd1be170d180b2baed755e8f0da547ceb267
+clone git github.com/docker/containerd 8508d2bec90b96403143a1104cdcbd56f6aeb361
 
 # cluster
 clone git github.com/docker/swarmkit 8a761950fb4d9251c335dc6149a8a02756cb3b10