Improve linting (prometheus-community#861)

* Disable unused-parameter check due to false positives on Collect() calls. * Enable misspell. * Simplify error returns. Signed-off-by: SuperQ <superq@gmail.com>

Author: SuperQ

.golangci.yml

@@ -1,6 +1,7 @@
 ---
 linters:
  enable:
+ - misspell
  - revive
 
 issues:
@@ -14,3 +15,9 @@ linters-settings:
  exclude-functions:
  # Never check for logger errors.
  - (github.com/go-kit/log.Logger).Log
+ revive:
+ rules:
+ # https://github.com/mgechev/revive/blob/master/RULES_DESCRIPTIONS.md#unused-parameter
+ - name: unused-parameter
+ severity: warning
+ disabled: true

collector/pg_database.go

@@ -115,10 +115,7 @@ func (c PGDatabaseCollector) Update(ctx context.Context, instance *instance, ch
 prometheus.GaugeValue, sizeMetric, datname,
 )
 }
-if err := rows.Err(); err != nil {
-return err
-}
-return nil
+return rows.Err()
 }
 
 func sliceContains(slice []string, s string) bool {

collector/pg_replication_slot.go

@@ -126,8 +126,5 @@ func (PGReplicationSlotCollector) Update(ctx context.Context, instance *instance
 prometheus.GaugeValue, isActiveValue, slotNameLabel,
 )
 }
-if err := rows.Err(); err != nil {
-return err
-}
-return nil
+return rows.Err()
 }

collector/pg_statio_user_tables.go

@@ -218,8 +218,5 @@ func (PGStatIOUserTablesCollector) Update(ctx context.Context, instance *instanc
 datnameLabel, schemanameLabel, relnameLabel,
 )
 }
-if err := rows.Err(); err != nil {
-return err
-}
-return nil
+return rows.Err()
 }