Introduce staticcheck for stricter builds (#7035)

cmd/rpc/pool.go

@@ -21,13 +21,6 @@ import (
 	"sync"
 )
 
-var b512pool = sync.Pool{
-	New: func() interface{} {
-		buf := make([]byte, 512)
-		return &buf
-	},
-}
-
 // A Pool is a type-safe wrapper around a sync.Pool.
 type Pool struct {
 	p *sync.Pool

cmd/rpc/server_test.go

@@ -77,11 +77,6 @@ func (t mytype) Foo(a *Auth, b *int) error {
 	return nil
 }
 
-// incompatible method because of unexported method.
-func (t mytype) foo(a *Auth, b *int) error {
-	return nil
-}
-
 // incompatible method because of first argument is not Authenticator.
 func (t *mytype) Bar(a, b *int) error {
 	return nil