Delete whole paths for lv2 plugins that did fail creating final ttl

There are plugins part of collections that fail on target postinst so
manifest.ttl is not created (cross and on-target failed - there is nothing left
we can do).
That causes warnings: an lv2 path without manifest: tse tse.
Shut these up by deleting whole path on target - right - binaries without
manifest.ttk are useless blobs.

Signed-off-by: Andreas Müller <schnitzeltony@gmail.com>

classes/lv2-turtle-helper.bbclass

@@ -121,8 +121,13 @@ pkg_postinst_ontarget_${PN_LV2}() {
     if [ -e ${LV2_POSTINST_MANIFEST} ]; then
         oldpath=`pwd`
         for sofile in `cat ${LV2_POSTINST_MANIFEST}`; do
-            cd `dirname "$sofile"`
-            lv2-ttl-generator "$sofile" || echo "Error: Turtle files for $sofile could not be created!"
+            lv2_path=`dirname "$sofile"`
+            cd "$lv2_path"
+            if ! lv2-ttl-generator "$sofile"; then
+                echo "Error: Turtle files for $sofile could not be created - remove $lv2_path!"
+                cd ..
+                rm -rf "$lv2_path"
+            fi
         done
         cd $oldpath
     fi