Fix a invalid memory reference error identified by gfortran

[weiwangncar]

Fix a memory problem in Noah LSM after PR#1641

TYPE: bug fix

KEYWORDS: memory issue, Noah LSM, WRF-Hydro

SOURCE: internal

DESCRIPTION OF CHANGES:
Problem:
After PR#1641 merge, which consisted modification and additions to NoahMP, problems showed up in the model when Noah LSM is used. Errors include random failures when running with a relatively large domain (581x501x56 in one test) and nests, and when model is trying to write output.

Solution:
Using 'configure -D' with gfortran identified the failure in module_sf_noahdrv.F. Examination of the routine suggests the code related to WRF-Hydro implementation could be an issue when WRF-Hydro is not used. Revision is made to the driver so that variables related to WRF-Hydro are properly defined when WRF-Hydro is not used or arrays are not defined.

LIST OF MODIFIED FILES:
M phys/module_sf_noahdrv.F
M phys/module_surface_driver.F

TESTS CONDUCTED:

1. Previously failed large domain and nest tests are working now.
2. The Jenkins tests are all passing.

[weiwangncar]

Test Type              | Expected  | Received |  Failed
= = = = = = = = = = = = = = = = = = = = = = = =  = = = =
Number of Tests        : 23           24
Number of Builds       : 60           58
Number of Simulations  : 158           156        0
Number of Comparisons  : 95           92        0

Failed Simulations are: 
None
Which comparisons are not bit-for-bit: 
None

[weiwangncar]

@smileMchen Can you take a look at this PR, and see if it is ok. If so, can you approve it?