jenkins: build a coverage report if GCOV is set (v2)
jenkins: build a coverage report if GCOV is set (v2)

v2: set umask to 0000. It's required to generate gcda, gcno files
Signed-off-by: Andrew Vagin <74c05afa918858348d6db8037d82fa8124870113@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@virtuozzo.com>

efiop/criu,efiop/criu,KKoukiou/criu-remote,AuthenticEshkinKot/criu,KKoukiou/criu-remote,efiop/criu,eabatalov/criu,AuthenticEshkinKot/criu,AuthenticEshkinKot/criu,eabatalov/criu,KKoukiou/criu-remote,eabatalov/criu,AuthenticEshkinKot/criu,KKoukiou/criu-remote,efiop/criu,efiop/criu,eabatalov/criu,AuthenticEshkinKot/criu,efiop/criu,AuthenticEshkinKot/criu,KKoukiou/criu-remote,eabatalov/criu,KKoukiou/criu-remote,eabatalov/criu