initialize the disk healer early on (#19143)

This PR fixes a bug that perhaps has been long introduced,
with no visible workarounds. In any deployment, if an entire
erasure set is deleted, there is no way the cluster recovers.

cmd/globals.go

@@ -379,13 +379,15 @@ var (
 		return *ptr
 	}
 
-	globalAllHealState *allHealState
+	globalAllHealState = newHealState(GlobalContext, true)
 
 	// The always present healing routine ready to heal objects
-	globalBackgroundHealRoutine *healRoutine
-	globalBackgroundHealState   *allHealState
+	globalBackgroundHealRoutine = newHealRoutine()
+	globalBackgroundHealState   = newHealState(GlobalContext, false)
 
-	globalMRFState mrfState
+	globalMRFState = mrfState{
+		opCh: make(chan partialOperation, mrfOpsQueueSize),
+	}
 
 	// If writes to FS backend should be O_SYNC.
 	globalFSOSync bool