Log warning when wireless plugin is used on unsupported platform (#4986)

plugins/inputs/wireless/wireless_nonlinux.go

@@ -0,0 +1,21 @@
+// +build !linux
+
+package wireless
+
+import (
+	"log"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+func (w *Wireless) Gather(acc telegraf.Accumulator) error {
+	return nil
+}
+
+func init() {
+	inputs.Add("wireless", func() telegraf.Input {
+		log.Print("W! [inputs.wireless] Current platform is not supported")
+		return &Wireless{}
+	})
+}