Change in coreboot[master]: tests: code coverage improvements

[Jakub Czapiga (Code Review)]

Attention is currently required from: Martin Roth, Paul Fagerburg, Julius Werner.
Jakub Czapiga has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/54072 )

Change subject: tests: code coverage improvements
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Patch Set 4: Code-Review+1

(3 comments)

File tests/Makefile.inc:

https://review.coreboot.org/c/coreboot/+/54072/comment/df65fd3b_09e3c2cc 
PS3, Line 199: coverage_rpt
> I had to add -tests to every target to get the main Makefile to use tests/Makefile.inc. […]

I was referring to directory name, not target name :)

File tests/Makefile.inc:

https://review.coreboot.org/c/coreboot/+/54072/comment/86985e79_b740d656 
PS4, Line 204: COV=1 $(MAKE) coverage-report
nit: What about V=1? V=$(V) might be useful in some cases.

https://review.coreboot.org/c/coreboot/+/54072/comment/c1ccab97_152d8884 
PS4, Line 207: COV=1 $(MAKE) clean-coverage-report
nit: Same as above