CLEANUP: namespaces: fix protection against multiple inclusions
The include file did not protect correctly against multiple inclusions,
as it didn't define the file name after checking for it. That's currently
harmless as the file is only included from .c but that could change.
diff --git a/include/common/namespace.h b/include/common/namespace.h
index e67742b..fa4185d 100644
--- a/include/common/namespace.h
+++ b/include/common/namespace.h
@@ -1,4 +1,5 @@
-#ifndef NAMESPACE_H
+#ifndef _NAMESPACE_H
+#define _NAMESPACE_H
#include <stdlib.h>
#include <ebistree.h>
@@ -21,4 +22,4 @@
int netns_init(void);
#endif /* CONFIG_HAP_NS */
-#endif /* NAMESPACE_H */
+#endif /* _NAMESPACE_H */