ecore_buffer: move include to out side of extern "C"

Summary: This fixes ecore_buffer_queue_init, shutdown compile error.

Test Plan:
1. compile with --enable-ecore-buffer
2. gcc -o ecore_buffer_consumer_example ecore_buffer_consumer_example.c \
   `pkg-config --libs --cflags eina ecore evas ecore-buffer ecore-evas`
3. check there is no error message like
`undefined reference to `ecore_buffer_queue_init'`

Reviewers: Hermet, zmike

Reviewed By: Hermet

Subscribers: cedric, #reviewers, #committers

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D6898

src/lib/ecore_buffer/Ecore_Buffer_Queue.h

@@ -1,6 +1,9 @@
 #ifndef _ECORE_BUFFER_QUEUE_H_
 #define _ECORE_BUFFER_QUEUE_H_
 
+#include <Eina.h>
+#include <Ecore_Buffer.h>
+
 #ifdef EAPI
 # undef EAPI
 #endif
@@ -31,8 +34,6 @@
 extern "C" {
 #endif
 
-#include <Eina.h>
-#include "Ecore_Buffer.h"
 
 /**
  * @defgroup Ecore_Buffer_Queue_Group Ecore Buffer Queue functions