packaging: replace `debs` folder by `artifacts`

In order to support new distribution not using .deb file format,
it should be better to call export folder `artifacts` instead of `debs`.

Change-Id: I21524fe535a4297851d87a66f2000a27efa565cc
diff --git a/extras/packaging/gnu-linux/ubuntu-20.Dockerfile b/extras/packaging/gnu-linux/ubuntu-20.Dockerfile
index 1930e01..c3047e8 100644
--- a/extras/packaging/gnu-linux/ubuntu-20.Dockerfile
+++ b/extras/packaging/gnu-linux/ubuntu-20.Dockerfile
@@ -10,7 +10,7 @@
     apt-get install -y \
         dialog apt-utils make devscripts build-essential debmake lintian \
     && apt-get clean && \
-    mkdir -p /build/debs
+    mkdir -p /build/artifacts
 
 RUN apt-get update && apt-get install -y \
         build-essential pkg-config cmake dpkg-dev gcc g++ git wget \
@@ -35,4 +35,4 @@
     debuild && \
     cd .. && \
     rm -Rf ${PKG_NAME} ${PKG_NAME}.tar.gz && \
-    cp /build/*.deb /build/debs/
+    cp /build/*.deb /build/artifacts/