btrfs: check for matching kernel send stream

btrfs: check for matching kernel send stream

The test case btrfs/049 is relevant to send stream version 2, and
needs kernel patches as well. So call _notrun if there isn't
matching kernel support as shown below

btrfs/047	 [not run] Missing btrfs kernel patch for send stream version 2, skipped this test
Not run: btrfs/047

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>