kmselement: Reduce critical regions
kmselement: Reduce critical regions

Change-Id: Ic8edf9bffb0d799d6e3bb447fbd9cd4fa3c0de09

KurentoLegacy/gst-kurento-plugins,ESTOS/kms-core,ESTOS/kms-core,shelsonjava/kms-core,TribeMedia/kms-core,shelsonjava/kms-core,Kurento/kms-core,KurentoLegacy/gst-kurento-plugins,Kurento/kms-core,ESTOS/kms-core,ESTOS/kms-core,Kurento/kms-core,KurentoLegacy/gst-kurento-plugins,KurentoLegacy/gst-kurento-plugins,TribeMedia/kms-core,shelsonjava/kms-core,shelsonjava/kms-core,TribeMedia/kms-core,TribeMedia/kms-core,Kurento/kms-core