[bugfix] Fix spacing issues when defining options for execution modes

[rsarm]

Fixes #1554

[codecov-io]

Codecov Report

Merging #1556 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #1556   +/-   ##
=======================================
  Coverage   88.03%   88.03%           
=======================================
  Files          44       44           
  Lines        6894     6897    +3     
=======================================
+ Hits         6069     6072    +3     
  Misses        825      825           

Impacted Files	Coverage Δ
reframe/frontend/cli.py	78.76% <100.00%> (+0.17%)	⬆️

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[vkarak]

Now that I see the fix, I don't think that this was actually a bug, but rather the configuration was wrong. Nonetheless, this will prevent common user errors in the future. Apart from the rest of the comments, we will need to adjust the unit test configuration to exercise this. Simply change the following two lines:

https://github.com/eth-cscs/reframe/blob/master/unittests/resources/settings.py#L134-L135

to

                '-c unittests/resources/checks/hellocheck.py',
                '-p builtin-gcc',

[vkarak]

lgtm now