[XFS] The forward declarations for the xfs_ioctl() helpers and the

associated comment about gcc behavior really aren't needed; all of these
functions are marked STATIC which includes noinline, and the stack usage
won't be a problem.

This effectively just removes the forward declarations and moves
xfs_ioctl() back to the end of the file.

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30534a

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>