btrfs: tests: properly initialize fs_info of extent buffer

The fs_info is supposed to be valid, even though it's not used right
now and the test does not crash.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2019-03-15 17:42:07 +01:00
commit 7b9586bc2b