BUILD: tree-wide: add several missing activity.h
A number of files currently access activity counters but rely on their
definitions to be inherited from other files (task.c, backend.c hlua.c,
sock.c, pool.c, stats.c, fd.c).
diff --git a/src/pool.c b/src/pool.c
index ad63d9b..e6669fb 100644
--- a/src/pool.c
+++ b/src/pool.c
@@ -11,7 +11,7 @@
*/
#include <errno.h>
-#include <haproxy/activity-t.h>
+#include <haproxy/activity.h>
#include <haproxy/api.h>
#include <haproxy/applet-t.h>
#include <haproxy/cfgparse.h>