[PATCH] Fix xfs build when CONFIG_XFS_POSIX_ACL=n

["Luck, Tony" <tony.luck@xxxxxxxxx>]

When CONFIG_XFS_POSIX_ACL is not set "xfs_check_acl" is #defined
to NULL - which breaks the code attempting to add a tracepoint
on this function.

Only define the tracepoint when the function exists.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>

---

Broken in linux-next for a few days by the "xfs: split xfs_itrace_entry"
commit. This patch should go after it (or better, should be merged into
it before this goes upstream).

diff --git a/fs/xfs/linux-2.6/xfs_trace.h b/fs/xfs/linux-2.6/xfs_trace.h
index 76de133..bb4803c 100644
--- a/fs/xfs/linux-2.6/xfs_trace.h
+++ b/fs/xfs/linux-2.6/xfs_trace.h
@@ -568,7 +568,9 @@ DEFINE_INODE_EVENT(xfs_readlink);
 DEFINE_INODE_EVENT(xfs_alloc_file_space);
 DEFINE_INODE_EVENT(xfs_free_file_space);
 DEFINE_INODE_EVENT(xfs_readdir);
+#ifdef CONFIG_XFS_POSIX_ACL
 DEFINE_INODE_EVENT(xfs_check_acl);
+#endif
 DEFINE_INODE_EVENT(xfs_vm_bmap);
 DEFINE_INODE_EVENT(xfs_file_ioctl);
 DEFINE_INODE_EVENT(xfs_file_compat_ioctl);