Btrfs: move fs/btrfs/ioctl.h to include/uapi/linux/btrfs.h

The header file will then be installed under /usr/include/linux so that
userspace applications can refer to Btrfs ioctls by name and use the same
structs used internally in the kernel.

Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index d3c3939..12bb841 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -21,8 +21,8 @@
 
 #include <linux/bio.h>
 #include <linux/sort.h>
+#include <linux/btrfs.h>
 #include "async-thread.h"
-#include "ioctl.h"
 
 #define BTRFS_STRIPE_LEN	(64 * 1024)