Fix an error that was introduced by me in a4a24280f2:

Using a pipe causes a subshell to be generated so the "exit" statements will
just leave the subshell. As a consequence, the sortedxxx.sh scripts produced
output but no error exit code. Which in turn caused an error in #2778 to slip
through undetected.

.github/checks/sorted_codeopt.sh

@@ -63,7 +63,8 @@ function checkarray
 }
 
 
-find "$CHECK_DIR" -name \*.\[ch\] -print | while read N; do
+FILES=$(find "$CHECK_DIR" -name \*.\[ch\] -print)
+for N in $FILES; do
     grep -q "BEGIN DECL SORTED_CODEOPT.SH" "$N" && checkarray "$N"
 done
 exit 0