build: reformat comments to pass go1.19 vet

See: https://go.dev/doc/go1.19#go-doc

backend/googlephotos/pattern.go

@@ -315,7 +315,7 @@ func yearMonthDayFilter(ctx context.Context, f lister, match []string) (sf api.S
 
 // featureFilter creates a filter for the Feature enum
 //
-// The API only supports one feature, FAVORITES, so hardcode that feature
+// The API only supports one feature, FAVORITES, so hardcode that feature.
 //
 // https://developers.google.com/photos/library/reference/rest/v1/mediaItems/search#FeatureFilter
 func featureFilter(ctx context.Context, f lister, match []string) (sf api.SearchFilter) {