XFS: Sysctl updates

Symlinks are created by default with mode 777 now, old behavior is
still accessible through sysctl through.  Irixsgid mount option
eprecated and it too is still accessible through sysctl.

Modid: 2.5.x-xfs:slinx:129282a

Documentation/filesystems/xfs.txt

@@ -29,12 +29,6 @@ When mounting an XFS filesystem, the following options are accepted.
 	The preferred buffered I/O size can also be altered on an
 	individual file basis using the ioctl(2) system call.
 
-  irixsgid
-	Do not inherit the ISGID bit on subdirectories of ISGID
-	directories, if the process creating the subdirectory
-	is not a member of the parent directory group ID.
-	This matches IRIX behavior.
-
   logbufs=value
 	Set the number of in-memory log buffers.  Valid numbers range
 	from 2-8 inclusive.