This patch makes the code adding PF_NOFREEZE conditional on the kernel 
version.
PF_NOFREEZE first showed up in 2.6.6-rc2

This allows the xenbus code to continue to compile against kernels pre 
2.6.6 - like SLES9 (2.6.5)

Patch: linux-xenbus-legacy.patch
Signed-off-by: Ben Guthro <bguthro@virtualiron.com>