Conditionally include <sys/shm.h> based on OS support. Define missing MAP_HUGETLB for Android.

Signed-off-by: Oleg Matcovschi <olegmatcovsky@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/backend.c b/backend.c
index d1fe964..e482fb8 100644
--- a/backend.c
+++ b/backend.c
@@ -34,12 +34,12 @@
 #include <sys/stat.h>
 #include <sys/wait.h>
 #include <sys/ipc.h>
-#ifndef FIO_NO_HAVE_SHM_H
-#include <sys/shm.h>
-#endif
 #include <sys/mman.h>
 
 #include "fio.h"
+#ifndef FIO_NO_HAVE_SHM_H
+#include <sys/shm.h>
+#endif
 #include "hash.h"
 #include "smalloc.h"
 #include "verify.h"