$NetBSD$
Fix a bashism
--- vendor/github.com/docker/docker/hack/dockerfile/install/containerd.installer.orig	2019-01-17 03:38:47.000000000 +0000
+++ vendor/github.com/docker/docker/hack/dockerfile/install/containerd.installer
@@ -19,7 +19,7 @@ install_containerd() {
 		export EXTRA_LDFLAGS='-extldflags "-fno-PIC -static"'
 
 		# Reset build flags to nothing if we want a dynbinary
-		if [ "$1" == "dynamic" ]; then
+		if [ "$1" = "dynamic" ]; then
 			export BUILDTAGS=''
 			export EXTRA_FLAGS=''
 			export EXTRA_LDFLAGS=''