Improve input argument check swlq

[angsch]

Description
Add missing checks for enforce assumptions on input parameters. Fix typos.

Checklist

• The documentation has been updated.
• If the PR solves a specific issue, it is set to be closed on merge.

[codecov]

Codecov Report

Merging #656 (27ece6c) into master (a7c0392) will not change coverage.
The diff coverage is 0.00%.

❗ Current head 27ece6c differs from pull request most recent head d1349aa. Consider uploading reports for the commit d1349aa to get more accurate results

@@           Coverage Diff           @@
##           master     #656   +/-   ##
=======================================
  Coverage    0.00%    0.00%           
=======================================
  Files        1894     1894           
  Lines      184050   184082   +32     
=======================================
- Misses     184050   184082   +32     

Impacted Files	Coverage Δ
SRC/cgemlqt.f	0.00% <0.00%> (ø)
SRC/clamswlq.f	0.00% <0.00%> (ø)
SRC/ctpmlqt.f	0.00% <0.00%> (ø)
SRC/dgemlqt.f	0.00% <0.00%> (ø)
SRC/dlamswlq.f	0.00% <0.00%> (ø)
SRC/dtpmlqt.f	0.00% <0.00%> (ø)
SRC/sgemlqt.f	0.00% <0.00%> (ø)
SRC/slamswlq.f	0.00% <0.00%> (ø)
SRC/stpmlqt.f	0.00% <0.00%> (ø)
SRC/zgemlqt.f	0.00% <0.00%> (ø)
... and 2 more

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[langou]

Thanks @angsch