Avoid using jsoniter, move to fastjson (#8063)

This is to avoid using unsafe.Pointer type
code dependency for MinIO, this causes
crashes on ARM64 platforms

Refer #8005 collection of runtime crashes due
to unsafe.Pointer usage incorrectly. We have
seen issues like this before when using
jsoniter library in the past.

This PR hopes to fix this using fastjson

cmd/xl-v1-metadata.go

@@ -28,7 +28,6 @@ import (
 	"sync"
 	"time"
 
-	jsoniter "github.com/json-iterator/go"
 	"github.com/minio/minio/cmd/logger"
 )
 
@@ -76,8 +75,9 @@ func (c ChecksumInfo) MarshalJSON() ([]byte, error) {
 
 // UnmarshalJSON - should never be called, instead xlMetaV1UnmarshalJSON() should be used.
 func (c *ChecksumInfo) UnmarshalJSON(data []byte) error {
+	logger.LogIf(context.Background(), errUnexpected)
+
 	var info checksumInfoJSON
-	var json = jsoniter.ConfigCompatibleWithStandardLibrary
 	if err := json.Unmarshal(data, &info); err != nil {
 		return err
 	}