modules/ims_usrloc_scscf: to avoid clang warning, include atomic_t declaration

modules/ims_usrloc_scscf/hslot.h

@@ -47,6 +47,7 @@
 #define HSLOT_H
 
 #include "../../locking.h"
+#include "../../atomic/atomic_common.h"
 
 #include "udomain.h"
 #include "impurecord.h"