xfs: fix missing header includes

Some of the xfs source files are missing header includes, so add them
back.  Sparse complains about non-static functions that don't have a
forward declaration anywhere.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/xfs_acl.c

@@ -13,8 +13,9 @@
 #include "xfs_attr.h"
 #include "xfs_trace.h"
 #include "xfs_error.h"
-#include <linux/posix_acl_xattr.h>
+#include "xfs_acl.h"
 
+#include <linux/posix_acl_xattr.h>
 
 /*
  * Locking scheme: