hw/net/ne2000-isa: Add guards to the header

Reviewed-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190412165416.7977-11-philmd@redhat.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

include/hw/net/ne2000-isa.h

@@ -6,6 +6,10 @@
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  */
+
+#ifndef HW_NET_NE2K_ISA_H
+#define HW_NET_NE2K_ISA_H
+
 #include "hw/hw.h"
 #include "hw/qdev.h"
 #include "hw/isa/isa.h"
@@ -31,3 +35,5 @@ static inline ISADevice *isa_ne2000_init(ISABus *bus, int base, int irq,
     }
     return d;
 }
+
+#endif