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_opcodes.sh

@@ -34,7 +34,8 @@ function checkarray_quoted_name
     rm -rf .a.tmp
 }
 
-find "$CHECK_DIR" -name \*.\[ch\] -print | while read N; do
+FILES=$(find "$CHECK_DIR" -name \*.\[ch\] -print)
+for N in $FILES; do
     grep -q "BEGIN SORTED_OPCODES.SH" "$N" && checkarray_quoted_name "$N"
 done
 exit 0