evaluate_steady_state.m: consistently use params

Prevents erroneously relying on stale parameters from M.params (thanks to Tom Holden); closes #1627

(manually cherry picked from commit c16c2fb8)
4 jobs for 4.5 in 56 minutes and 55 seconds (queued for 7 seconds)
Status Job ID Name Coverage
  Build
passed #1376
build_binaries

00:08:59

passed #1377
build_doc

00:00:54

 
  Test
failed #1378
testsuite_matlab

00:47:55

manual #1379
allowed to fail manual
testsuite_octave_manual
 
Name Stage Failure
failed
testsuite_matlab Test
tests/*.m.log: found 31 matching files             
tests/*.m.trs: found 31 matching files

tests/*/*.m.log: found 222 matching files

tests/*/*.m.trs: found 222 matching files

tests/*/*/*.m.log: found 104 matching files

tests/*/*/*.m.trs: found 104 matching files

tests/run_test_matlab_output.txt: found 1 matching files

Uploading artifacts to coordinator... ok
id=1378 responseStatus=201 Created token=JShGX8KN
ERROR: Job failed: exit status 1