build: add include guards for a couple elm headers

Reviewed-by: Stefan Schmidt <stefan@datenfreihafen.org>
Differential Revision: https://phab.enlightenment.org/D9973

src/lib/elementary/elm_general.h

@@ -1,3 +1,5 @@
+#ifndef _ELM_GENERAL_H
+#define _ELM_GENERAL_H
 /**
  * @defgroup Elm_General General
  * @ingroup Elementary
@@ -821,3 +823,4 @@ typedef enum
 /**
  * @}
  */
+#endif

src/lib/elementary/elm_scroller_legacy.h

@@ -1,3 +1,5 @@
+#ifndef _ELM_SCROLLER_LEGACY_H
+#define _ELM_SCROLLER_LEGACY_H
 #ifndef _ELM_INTERFACE_SCROLLABLE_EO_TYPES
 #define _ELM_INTERFACE_SCROLLABLE_EO_TYPES
 
@@ -637,3 +639,4 @@ EAPI void elm_scroller_propagate_events_set(Evas_Object *obj, Eina_Bool propagat
  * @ingroup Elm_Scroller
  */
 EAPI Eina_Bool elm_scroller_propagate_events_get(const Evas_Object *obj);
+#endif