Adjust cli option (#7418)

* adjust "weed benchmark" CLI to use readOnly/writeOnly

* consistently use "-master" CLI option

* If both -readOnly and -writeOnly are specified, the current logic silently allows it with -writeOnly taking precedence. This is confusing and could lead to unexpected behavior.

weed/command/master.go

@@ -45,6 +45,7 @@ type MasterOptions struct {
 	ipBind                     *string
 	metaFolder                 *string
 	peers                      *string
+	mastersDeprecated          *string // deprecated, for backward compatibility in master.follower
 	volumeSizeLimitMB          *uint
 	volumePreallocate          *bool
 	maxParallelVacuumPerServer *int