Btrfs: update send_progress at correct places

Updating send_progress in process_recorded_refs was not correct.
It got updated too early in the cur_inode_new_gen case.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Reported-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Alexander Block <ablock84@googlemail.com>