Fix a couple of mistakes and improve DRYness

- `cat` should have been `echo`
- remove debugging setting
- refactor a few lines in api_call()

Author: mhucka

dev_tools/ci/size-labeler.sh

@@ -79,7 +79,6 @@ function jq_file() {
 }
 
 function api_call() {
-    set -x
     local -r endpoint="${1// /%20}" # love that our label names have spaces...
     local -r uri="https://api.github.com/repos/${GITHUB_REPOSITORY}"
     local -r url="${uri}/${endpoint}"
@@ -96,12 +95,11 @@ function api_call() {
     response_body=$(curl "${curl_opts[@]}" "${@:2}" "${url}")
     local exit_status=$?
     set -e
+    echo "${response_body}"
     if [[ $exit_status -ne 0 ]]; then
         error "GitHub API call failed (curl exit $exit_status) for ${url}"
-        cat "${response_body}"
         exit $exit_status
     fi
-    echo "${response_body}"
 }
 
 function compute_changes() {