scripts: don't hardcode architecture in e2e script

Signed-off-by: Laura Brehm <laurabrehm@hey.com>

scripts/test/e2e/run

@@ -2,6 +2,8 @@
 # Run integration tests against the latest docker-ce dind
 set -eu -o pipefail
 
+source ./scripts/build/.variables
+
 container_ip() {
     local cid=$1
     local network=$2
@@ -69,7 +71,7 @@ runtests() {
         GOPATH="$GOPATH" \
         PATH="$PWD/build/:/usr/bin:/usr/local/bin:/usr/local/go/bin" \
         HOME="$HOME" \
-        DOCKER_CLI_E2E_PLUGINS_EXTRA_DIRS="$PWD/build/plugins-linux-amd64" \
+        DOCKER_CLI_E2E_PLUGINS_EXTRA_DIRS="$PWD/build/plugins-linux-${GOARCH}" \
         GO111MODULE=auto \
         "$(command -v gotestsum)" -- ${TESTDIRS:-./e2e/...} ${TESTFLAGS-}
 }