bug: Sampling Error Correction doesn't affect adaptive inflation updates

Sampling error correction does not appear to impact the adaptive inflation updates.

The value of the sampling error correction is read from the table in subroutine update_from_obs_inc in assim_tools_mod.f90. It is then used to modify the value of the reg_coef which is subsequently multiplied by the obs_inc to get the state_inc which is returned. The updated value of the reg_coef is also returned to the calling location in subroutine obs_updates_ens. However, the reg_coef is a local variable array in obs_update_ens and is not returned from this subroutine. Subroutine update_varying_state_space_inflation does not make any use of the sampling error correction table. It seems like it would be appropriate to apply sampling error correction to reduce the strength of the relation between the observation and state variable when updating the inflation, too.

The current behavior has been unchanged since the original implementation of the adaptive inflation algorithms. Should we update the behavior to include the use of sampling error correction, or should we document that it is not being done?