admin: Export HealStatus data type (minio#3930)

`healStatus` can be returned to the API caller. This commit will help
developers to declare a variable with HealStatus type.

pkg/madmin/API.md

@@ -287,7 +287,7 @@ List ongoing multipart uploads that need healing.
 |---|---|---|
 |`ui.Key` | _string_ | Name of the object being uploaded |
 |`ui.UploadID` | _string_ | UploadID of the ongoing multipart upload |
-|`ui.HealUploadInfo.Status` | _healStatus_| One of `Healthy`, `CanHeal`, `Corrupted`, `QuorumUnavailable`|
+|`ui.HealUploadInfo.Status` | _HealStatus_| One of `Healthy`, `CanHeal`, `Corrupted`, `QuorumUnavailable`|
 |`ui.Err`| _error_ | non-nil if fetching fetching healing information failed |
 
 __Example__

pkg/madmin/heal-commands.go

@@ -95,11 +95,11 @@ type ListBucketsHealResponse struct {
 }
 
 // HealStatus - represents different states of healing an object could be in.
-type healStatus int
+type HealStatus int
 
 const (
 	// Healthy - Object that is already healthy
-	Healthy healStatus = iota
+	Healthy HealStatus = iota
 	// CanHeal - Object can be healed
 	CanHeal
 	// Corrupted - Object can't be healed
@@ -110,7 +110,7 @@ const (
 
 // HealBucketInfo - represents healing related information of a bucket.
 type HealBucketInfo struct {
-	Status healStatus
+	Status HealStatus
 }
 
 // BucketInfo - represents bucket metadata.
@@ -127,7 +127,7 @@ type BucketInfo struct {
 
 // HealObjectInfo - represents healing related information of an object.
 type HealObjectInfo struct {
-	Status              healStatus
+	Status              HealStatus
 	MissingDataCount    int
 	MissingPartityCount int
 }