monin_obukhov tests: Avoid continuation lines containing only a comment

[J-Lentz]

Description
The Cray compiler does not like continuation lines which contain only a comment. For example, the following will result in a syntax error:

real, parameter :: g = 9.81 &
& !< Acceleration due to gravity (m / s^2)

The workaround is to move the comment onto the same line as the variable declaration.

How Has This Been Tested?
monin_obukhov tests build with CCE 18 on C5.

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