sanitycheck: fix --coverage-tool gcovr

Currently '--coverage-tool gcovr' results in using lcov. Fix that to use
gcovr, as requested by user.

Fixes: f6462a3a8c61 ("sanitycheck: get rid of global VERBOSE")
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
1 file changed