build-docs.jpl: Archive build dir if build fail

Archive build dir if build fail. The artifacts can help to investigate
into the error cause.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: I3ab6d64cc39b8b735e10741846344ff386607efa
diff --git a/jenkins/build-docs.jpl b/jenkins/build-docs.jpl
index 934f902..aa8bc65 100644
--- a/jenkins/build-docs.jpl
+++ b/jenkins/build-docs.jpl
@@ -28,6 +28,9 @@
         archiveArtifacts 'trusted-firmware-m/build/docs/**'
       }
     } catch (Exception e) {
+      stage("Post") {
+        archiveArtifacts 'trusted-firmware-m/build/**'
+      }
       manager.buildFailure()
       verify = -1
     } finally {