Use code generation to set IAMSTATIC instead of -X

Signed-off-by: Michael Hudson-Doyle <michael.hudson@linaro.org>

hack/make/dynbinary

@@ -5,6 +5,14 @@ DEST=$1
 
 if [ -z "$DOCKER_CLIENTONLY" ]; then
 	# dockerinit still needs to be a static binary, even if docker is dynamic
+	cat > dockerversion/static.go <<EOF
+// AUTOGENERATED FILE; see hack/make/binary and hack/make/dynbinary
+package dockerversion
+
+func init() {
+	IAMSTATIC = true
+}
+EOF
 	go build \
 		-o "$DEST/dockerinit-$VERSION" \
 		"${BUILDFLAGS[@]}" \
@@ -40,6 +48,7 @@ fi
 
 (
 	export LDFLAGS_STATIC_DOCKER="-X $DOCKER_PKG/dockerversion.INITSHA1 \"$DOCKER_INITSHA1\" -X $DOCKER_PKG/dockerversion.INITPATH \"$DOCKER_INITPATH\""
+	export IAMSTATIC=false
 	export BUILDFLAGS=( "${BUILDFLAGS[@]/netgo /}" ) # disable netgo, since we don't need it for a dynamic binary
 	source "$(dirname "$BASH_SOURCE")/binary"
 )