refactor: clean up code quality issues

Remove no-op assignment (calculatedPort = calculatedPort) that had no effect.
The variable already holds the correct value when no alternative port is
found.

Improve documentation for the defensive gRPC port initialization fallback
in startAdminServer. While this code shouldn't execute in normal flow
because ensureAllPortsAvailableOnIP is called earlier in runMini, the
fallback handles edge cases where port initialization may have been skipped
or failed silently due to configuration changes or error handling paths.

weed/command/mini.go

@@ -527,7 +527,6 @@ func initializeGrpcPortsOnIP(bindIp string) {
 				newPort := findAvailablePortOnIP(bindIp, calculatedPort+1, 100, allocatedGrpcPorts)
 				if newPort == 0 {
 					glog.Errorf("Could not find available gRPC port for %s starting from %d, will use calculated %d and fail on binding", config.name, calculatedPort+1, calculatedPort)
-					calculatedPort = calculatedPort
 				} else {
 					calculatedPort = newPort
 					glog.Infof("gRPC port %d for %s is available, using it instead of calculated %d", newPort, config.name, *config.httpPort+GrpcPortOffset)
@@ -935,6 +934,8 @@ func startMiniAdminWithWorker(allServicesReady chan struct{}) {
 
 	// gRPC port should have been initialized by ensureAllPortsAvailableOnIP in runMini
 	// If it's still 0, that indicates a problem with the port initialization sequence
+	// This defensive fallback handles edge cases where port initialization may have been skipped
+	// or failed silently (e.g., due to configuration changes or error handling paths)
 	if *miniAdminOptions.grpcPort == 0 {
 		glog.Warningf("Admin gRPC port was not initialized before startAdminServer, attempting fallback initialization...")
 		// Use the same availability checking logic as initializeGrpcPortsOnIP