Appease gcc in regards to "warning: 'rtx' is used uninitialized in
this function".

SGI-PV: 907752
SGI-Modid: xfs-linux-melb:xfs-kern:29007a
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTim Shimmin <tes@sgi.com>