staging: lustre: cfs_percpt_alloc: use kvmalloc(GFP_KERNEL)

this allocation is called from several places, but all are
during initialization, so GFP_NOFS is not needed.
So use kvmalloc and GFP_KERNEL.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>