ktest: Run commands through list-form shell open

run_command() currently uses string-form open():

  open(CMD, "$command 2>&1 |")

That delegates parsing to the shell but also mixes the stderr redirection
into the command string. Switch to list-form open() with an explicit sh -c
wrapper so shell syntax errors are captured in the same output stream as
command output. Otherwise, important errors can not be retrieved from the
ktest LOG_FILE.

Cc: John Hawley <[email protected]>
Cc: Andrea Righi <[email protected]>
Cc: Marcos Paulo de Souza <[email protected]>
Cc: Matthieu Baerts <[email protected]>
Cc: Fernando Fernandez Mancera <[email protected]>
Cc: Pedro Falcato <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Ricardo B. Marlière <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

Author: rbmarliere

tools/testing/ktest/ktest.pl

@@ -1921,7 +1921,10 @@ sub run_command {
     doprint("$command ... ");
     $start_time = time;
 
-    $pid = open(CMD, "$command 2>&1 |") or
+    $pid = open(CMD, "-|",
+		"sh", "-c",
+		'command=$1; shift; exec 2>&1; eval "$command"',
+		"sh", $command) or
 	(fail "unable to exec $command" and return 0);
 
     if (defined($opt{"LOG_FILE"})) {