Further code cleanup for SCM and FV3

[grantfirl]

These changes clean up the following:

• Fortran 2018 deleted feature warnings in GNU 9.1 for cu_gf_deep.F90 and module_sf_ruclsm.F90 (Fortran 77 shared do loop endings and do loop ending that is neither continue or end do)
• Uninitialized intent(out) variable warnings in Intel 18: cu_gf_driver.F90, cu_ntiedtke.F90, module_gfdl_cloud_microphys.F90, mp_thompson_post.F90, satmedmfvdif.F
• division by zero in an if test and an extraneous operator (+) in micro_mg3_0.F90
• different logical argument types in sfcsub.F
• remove comment about HYBRID CCPP mode (see https://github.com/NCAR/NEMSfv3gfs/pull/162 for a description)

These need to be put through regression tests in FV3, which will be done as part of @climbfuji work to remove the hybrid build.

These changes also form a subset of the branch ccpp_release_3_work that is required to work with the SCM.

[climbfuji]

Associated PRs:

NCAR/ccpp-framework#192
#251
https://github.com/NCAR/NEMS/pull/35
https://github.com/NCAR/FV3/pull/158
https://github.com/NCAR/NEMSfv3gfs/pull/162

[grantfirl]

This needs approval by @climbfuji or @llpcarson since it originated with me.

[climbfuji]

Approved. These changes have been tested with NEMSfv3gfs (see associated PRs listed in the comments).