src/artifacts: break when parent was found in references

Otherwise we can potentially overwrite 'target' and thus leak the
storage it pointed to.

Discovered by coverity.

Signed-off-by: Enrico Joerns <[email protected]>

src/artifacts.c

@@ -513,6 +513,7 @@ gboolean r_artifact_repo_commit(RArtifactRepo *repo, GError **error)
 							artifact->name,
 							artifact->checksum.digest
 							);
+					break;
 				} else {
 					g_debug("disabled");
 				}