kmssdpsession: use g_clear_error instead of g_error_free
kmssdpsession: use g_clear_error instead of g_error_free

Change-Id: I84e7b4f2add0e87ea0b9c57a5bb8a2b585a656fe

ESTOS/kms-core,ESTOS/kms-core,ESTOS/kms-core,ESTOS/kms-core,Kurento/kms-core,Kurento/kms-core,Kurento/kms-core,Kurento/kms-core