LU-1538 tests: standardize test script init – parallel-scale

LU-1538 tests: standardize test script init – parallel-scale

Standardize the initial Lustre test script initialization for
clarity and consistency for all parallel-scale tests.

The LUSTRE path is already normalized in init_test_env(), so this
doesn't need to be done in the caller.  Use $(...) subshells instead
of `...` in the affected lines.  Remove NAME, SRCDIR, PATH, MULTIOP,
SETUP, CLEANUP, CHECKSTAT, TMP, SAVE_PWD, variable initialization,
since it is already done in init_test_env() or not needed in the test
scripts.

Move all definitions of ALWAYS_EXCEPT and SLOW to after
init_test_env() and init_logging() and call build_test_filter()
immediately after the ALWAYS_EXCEPT and SLOW definitions.

Test-Parameters: trivial
Test-Parameters: envdefinitions=SLOW=yes,ENABLE_QUOTA=yes clientdistro=el7.8 clientcount=2 osscount=1 ostcount=7 mdscount=1 mdtcount=1 austeroptions=-R testlist=parallel-scale-nfsv4
Test-Parameters: envdefinitions=SLOW=yes,ENABLE_QUOTA=yes clientdistro=el7.8 clientcount=2 osscount=1 ostcount=7 mdscount=1 mdtcount=1 austeroptions=-R testlist=parallel-scale,parallel-scale-nfsv3
Signed-off-by: James Nunez <jnunez@whamcloud.com>
Change-Id: I5690f17033ca92e5578c579e81cbcc024ca7f770
Reviewed-on: https://review.whamcloud.com/36355
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Emoly Liu <emoly@whamcloud.com>
Reviewed-by: Wei Liu <sarah@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>