Fix compilation in mariabackup

Compilation got confused  about 2 wsrep.h headers in include path
Rename backup's wsrep.h to backup_wsrep.h to fixO

extra/mariabackup/wsrep.h → extra/mariabackup/backup_wsrep.h

@@ -19,8 +19,8 @@ along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 *******************************************************/
 
-#ifndef WSREP_H
-#define WSREP_H
+#ifndef MARIABACKUP_WSREP_H
+#define MARIABACKUP_WSREP_H
 
 /***********************************************************************
 Store Galera checkpoint info in the 'xtrabackup_galera_info' file, if that

extra/mariabackup/wsrep.cc

@@ -46,6 +46,7 @@ permission notice:
 #include <trx0sys.h>
 
 #include "common.h"
+#include "backup_wsrep.h"
 #ifdef WITH_WSREP
 #define WSREP_XID_PREFIX "WSREPXid"
 #define WSREP_XID_PREFIX_LEN MYSQL_XID_PREFIX_LEN

extra/mariabackup/xtrabackup.cc

@@ -85,7 +85,7 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #include "xbstream.h"
 #include "changed_page_bitmap.h"
 #include "read_filt.h"
-#include "wsrep.h"
+#include "backup_wsrep.h"
 #include "innobackupex.h"
 #include "backup_mysql.h"
 #include "backup_copy.h"