Fix updating failed file snapshots

Author: SjorsO

src/MatchesSnapshots.php

@@ -216,6 +216,8 @@ protected function doFileSnapshotAssertion(string $filePath)
                 $fileSystem->copy($filePath, $snapshotId);
 
                 $this->registerSnapshotChange("File snapshot updated for {$snapshotId}");
+
+                return;
             }
 
             $fileSystem->copy($filePath, $failedSnapshotId);