xfs: Fix build when CONFIG_XFS_POSIX_ACL=n

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@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/linux-2.6/xfs_trace.h

@@ -571,7 +571,9 @@ 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);