Please fix test failures from GNU grep change.

[bremner]

Recently in v3.5 (November 2020?) GNU grep made the following change
"The message that a binary file matches is now sent to standard error". This causes 16 tests to fail, since they run "grep SOMTHING log.s2c | wc -l" and log.s2c is considered a binary file.
In Debian (1) I proposed using "grep -c" instead, as this seems to have the desired behavior on binary files. I'm not sure this is the best approach in general. Alternatives include

• redirecting standard error
• running grep with the "-a" option (not sure how portable that is).