make check error

[Dmitri A. Sergatskov]

Looks bizarre.

E.g.:

http://buildbot.octave.org:8010/#/builders/9/builds/597/steps/6/logs/stdio

<<<<

>>>>> processing /home/buildbotu/fc25-x86_64/clang-fedora/build/libinterp/corefcn/dassl.cc-tst
>>>>> processing /home/buildbotu/fc25-x86_64/clang-fedora/build/libinterp/corefcn/data.cc-tst
***** error <Invalid call to diag> diag ()
!!!!! error failed.
Expected <Invalid call to diag>, but got <unable to open /home/buildbotu/fc25-x86_64/clang-fedora/build/../src/doc/interpreter/macros.texi for reading>
***** error <Invalid call to diag> diag (1,2,3,4)
!!!!! error failed.
Expected <Invalid call to diag>, but got <unable to open /home/buildbotu/fc25-x86_64/clang-fedora/build/../src/doc/interpreter/macros.texi for reading>
>>>>