scripts: Fix coverage information downloading script

Fix COVERAGE_DIR parsing from results by using the `-m 1` option in
`grep` command to limit the output to a single match.

Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>

scripts/download_packit_coverage.sh

@@ -134,7 +134,7 @@ fi
 # now we have TF_ARTIFACTS_URL so we can proceed with the download
 echo "TF_ARTIFACTS_URL=${TF_ARTIFACTS_URL}"
 
-COVERAGE_DIR=$( curl --retry 5 ${TF_ARTIFACTS_URL}/results.xml | grep -E -o "${TF_ARTIFACTS_URL}.*${TF_COVERAGE_DATA_DIR}" )
+COVERAGE_DIR=$( curl --retry 5 ${TF_ARTIFACTS_URL}/results.xml | grep -E -m 1 -o "${TF_ARTIFACTS_URL}.*${TF_COVERAGE_DATA_DIR}" )
 echo "COVERAGE_DIR=${COVERAGE_DIR}"
 
 DOWNLOADED="False"