fix vet errors

store/files_metadata.go

@@ -65,7 +65,7 @@ func (st *Store) SyncFileMetadataFromFile(group string, id uint64) error {
 				return fmt.Errorf("ffprobe returned %d", status.ExitStatus())
 			}
 		}
-		return fmt.Errorf("getting exit code of ffprobe failed:", err)
+		return fmt.Errorf("getting exit code of ffprobe failed: %v", err)
 	}
 
 	var output ffprobeOutput
@@ -75,7 +75,7 @@ func (st *Store) SyncFileMetadataFromFile(group string, id uint64) error {
 	}
 	d, err := time.ParseDuration(output.Format.DurationSec + "s")
 	if err != nil {
-		return fmt.Errorf("unable to parse duration from ffprobe output:", err)
+		return fmt.Errorf("unable to parse duration from ffprobe output: %v", err)
 	}
 
 	// TODO: store metadata in database