remove fms2io_init in interpolator_mod

[mlee03]

Description
This PR removes the subroutine fms2io_init . All code in fms2io_init is involved in initialization and is moved to subroutine interpolator_init instead.

Fixes #1309

How Has This Been Tested?
Make passes with the latest Intel and GCC on the AMD box

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• New check tests, if applicable, are included
• make distcheck passes