workflows: count number of Coverity issues

The output of `cov-format-errors --text-output-style multiline` outputs
two paragraphs per issue: the first paragraph mentions only the line
which triggered the issue, while the second paragraph includes a trace
of the analysis through which Coverity concluded that this is an issue.

Each paragraph is followed by a single blank line, which we count here.
Note that this does not rely on the output format being stable in the
long term; the count is merely needed during the transition period of
resolving the remaining issues, after which it may be replaced with a
check that the output of `cov-format-errors` is empty.

This provides the count for #245

Author: pcolberg

.github/workflows/coverity.yml

@@ -66,6 +66,7 @@ jobs:
       - run: cov-analyze --config config.xml --dir results --concurrency --security --rule --enable-constraint-fpp --enable-fnptr --enable-virtual
       - run: cov-format-errors --text-output-style multiline --dir results --filesort --file "$PWD" --strip-path "$PWD" > cov-errors.txt
       - run: cat cov-errors.txt
+      - run: count=$(grep -c '^$' cov-errors.txt) && echo "$(( $count / 2 ))"
       - uses: actions/upload-artifact@v3
         with:
           name: fpga-runtime-for-opencl-${{ github.sha }}-coverity-${{ github.run_id }}