Document why certain LTP tests fail.

[marcinslusarz]

This change is 

[krzycz]

---

Reviewed 1 of 1 files at r1. Review status: all files reviewed at latest revision, all discussions resolved, some commit checks failed.

---

Comments from Reviewable

[codecov[bot]]

Codecov Report

Merging #404 into master will increase coverage by 0.01%. The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #404      +/-   ##
==========================================
+ Coverage   77.02%   77.03%   +0.01%     
==========================================
  Files          67       67              
  Lines        8330     8330              
  Branches     1678     1678              
==========================================
+ Hits         6416     6417       +1     
+ Misses       1496     1495       -1     
  Partials      418      418

Flag	Coverage Δ
#ltp_tests	46.46% <ø> (+0.01%)	:arrow_up:
#sqlite_tests	45.14% <ø> (ø)	:arrow_up:
#tests_antool	15.24% <ø> (ø)	:arrow_up:
#tests_posix_multi_threaded	25.06% <ø> (ø)	:arrow_up:
#tests_posix_single_threaded	54.21% <ø> (ø)	:arrow_up:
#tests_preload	44.67% <ø> (-0.01%)	:arrow_down:

Impacted Files	Coverage Δ
src/libpmemfile-posix/rename.c	90.87% <0%> (-0.4%)	:arrow_down:
src/libpmemfile-posix/dir.c	85.5% <0%> (+0.49%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update af1a8ce...7b2e829. Read the comment docs.

[GBuella]

---

Reviewed 1 of 1 files at r1, 1 of 1 files at r2. Review status: all files reviewed at latest revision, all discussions resolved.

---

Comments from Reviewable