fix more warnings

7 jobs for master in 3 minutes and 39 seconds
Status Name Job ID Coverage
  Test
passed clang-c++11 #13991
Linux

00:02:25

passed clang-c++98 #13993
Linux

00:01:39

passed cppcheck #13996
Linux

00:01:46

passed gcc-c++11 #13990
Linux

00:03:38

passed gcc-c++98 #13992
Linux

00:02:33

passed macos-c++11 #13994
Apple

00:02:28

passed macos-c++98 #13995
Apple

00:02:19