Fix variable export typo in Dockerfile

BUG=None
TEST=manual

Change-Id: Ia24a75c09c2384768557a694b72881b47ac1ea97
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/moblab/+/5238441
Commit-Queue: Varun Thammineni <varunth@google.com>
Tested-by: Varun Thammineni <varunth@google.com>
Reviewed-by: Varun Thammineni <varunth@google.com>
diff --git a/src/dockerfiles/remote_access/Dockerfile b/src/dockerfiles/remote_access/Dockerfile
index ce43c32..c4e10b6 100644
--- a/src/dockerfiles/remote_access/Dockerfile
+++ b/src/dockerfiles/remote_access/Dockerfile
@@ -65,7 +65,7 @@
     libffi-dev
 
 RUN echo "chown \"\$USER_NAME\":\"\$USER_NAME\" /home/\"\$USER_NAME\"" >> /etc/cont-init.d/10-adduser
-RUN echo "export \$HOME=/home/\"\$USER_NAME\"" >> /etc/cont-init.d/10-adduser
+RUN echo "export HOME=/home/\"\$USER_NAME\"" >> /etc/cont-init.d/10-adduser
 RUN echo "addgroup --gid 412 docker" >> /etc/cont-init.d/10-adduser
 RUN echo "usermod -aG docker moblab" >> /etc/cont-init.d/10-adduser