Fix a bug in coverage reporting.
Fix a bug in coverage reporting.

The directory from where the source files are sought when producing a
coverage report in text or XML format should not be the build directory
but the source directory instead.

MathieuDuponchelle/meson,QuLogic/meson,aaronp24/meson,centricular/meson,jeandet/meson,centricular/meson,mesonbuild/meson,trhd/meson,becm/meson,MathieuDuponchelle/meson,becm/meson,becm/meson,rhd/meson,centricular/meson,thiblahute/meson,QuLogic/meson,aaronp24/meson,fmuellner/meson,wberrier/meson,wberrier/meson,pexip/meson,thiblahute/meson,ernestask/meson,pexip/meson,trhd/meson,trhd/meson,jpakkane/meson,centricular/meson,becm/meson,pexip/meson,centricular/meson,jeandet/meson,germandiagogomez/meson,jpakkane/meson,jpakkane/meson,germandiagogomez/meson,aaronp24/meson,aaronp24/meson,fmuellner/meson,trhd/meson,jeandet/meson,germandiagogomez/meson,ernestask/meson,jpakkane/meson,mesonbuild/meson,thiblahute/meson,wberrier/meson,jeandet/meson,MathieuDuponchelle/meson,QuLogic/meson,MathieuDuponchelle/meson,jpakkane/meson,QuLogic/meson,ernestask/meson,aaronp24/meson,centricular/meson,rhd/meson,trhd/meson,mesonbuild/meson,trhd/meson,pexip/meson,becm/meson,germandiagogomez/meson,rhd/meson,rhd/meson,jpakkane/meson,pexip/meson,fmuellner/meson,wberrier/meson,mesonbuild/meson,QuLogic/meson,jpakkane/meson,ernestask/meson,mesonbuild/meson,rhd/meson,thiblahute/meson,mesonbuild/meson,jeandet/meson,trhd/meson,becm/meson,thiblahute/meson,jeandet/meson,aaronp24/meson,QuLogic/meson,germandiagogomez/meson,rhd/meson,becm/meson,aaronp24/meson,fmuellner/meson,MathieuDuponchelle/meson,trhd/meson,centricular/meson,QuLogic/meson,mesonbuild/meson,QuLogic/meson,MathieuDuponchelle/meson,MathieuDuponchelle/meson,ernestask/meson,fmuellner/meson,wberrier/meson,jeandet/meson,germandiagogomez/meson,thiblahute/meson,thiblahute/meson,fmuellner/meson,ernestask/meson,QuLogic/meson,fmuellner/meson,mesonbuild/meson,rhd/meson,mesonbuild/meson,thiblahute/meson,jpakkane/meson,becm/meson,wberrier/meson,becm/meson,wberrier/meson,jpakkane/meson,wberrier/meson,jeandet/meson,pexip/meson,fmuellner/meson,MathieuDuponchelle/meson,mesonbuild/meson,centricular/meson,pexip/meson,ernestask/meson,MathieuDuponchelle/meson,ernestask/meson,trhd/meson,ernestask/meson,aaronp24/meson,pexip/meson,pexip/meson,rhd/meson,becm/meson,germandiagogomez/meson,aaronp24/meson,fmuellner/meson,jeandet/meson,thiblahute/meson,pexip/meson