staging: lustre: Convert more LIBCFS_ALLOC allocation to direct GFP_KERNEL

None of these need to be GFP_NOFS, so use GFP_KERNEL explicitly
with kmalloc(), kvmalloc(), or kvmalloc_array().
Change matching LIBCFS_FREE() to kfree() or kvfree()

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