Fix recent QC crash

[mattdturner]

PR checklist

• Short (1 sentence) summary of your PR:
  Edit the QC script to fix an oversight in Issue333 #337
• Developer(s):
  @mattdturner
• Suggest PR reviewers from list in the column to the right.
• Please copy the PR test results link or provide a summary of testing completed below.
  N/A
• How much do the PR code changes differ from the unmodified code?
  • bit for bit
  • different at roundoff level
  • more substantial
• Does this PR create or have dependencies on Icepack or any other models?
  • Yes
  • No
• Does this PR add any new test cases?
  • Yes
  • No
• Is the documentation being updated? ("Documentation" includes information on the wiki or in the .rst files from doc/source/, which are used to create the online technical docs at https://readthedocs.org/projects/cice-consortium-cice/.)
  • Yes
  • No, does the documentation need to be updated at a later time?
    • Yes
    • No
• Please provide any additional information or relevant details below:
  • The fix implemented in this PR is identical to the fix in Issue333 #337 .
  • PR Issue333 #337 implemented the fix in 1 location that had the problem, but there were 2 spots in the code with the same exact problem.
  • I tested this updated script on the @abouchat output data provided in qc environment setup #333 and the test completed with the following output

INFO:__main__:Running QC test on the following directories:
INFO:__main__:  /p/work1/turner/cice_qc_debug/brooks_intel_smoke_gx1_44x1_alt02_medium_qc.qc_base_original_alt02/
INFO:__main__:  /p/work1/turner/cice_qc_debug/brooks_intel_smoke_gx1_44x1_alt02_medium_qc.qc_test_alt02/
INFO:__main__:Number of files: 1825
INFO:__main__:2 Stage Test Passed
INFO:__main__:Quadratic Skill Test Failed for Northern Hemisphere
INFO:__main__:Quadratic Skill Test Failed for Southern Hemisphere
INFO:__main__:
ERROR:__main__:Quality Control Test FAILED

[mattdturner]

For reference to the skill test failures, the skill scores were;

DEBUG:__main__:Northern Hemisphere skill score = 0.979277
DEBUG:__main__:Southern Hemisphere skill score = 0.912965