selftests/ftrace: Add --console hidden option

Add --console hidden option for debug test cases.

This option allows to put "sh" or something else
when the test case hits a bug.

For example, if you find a testcase which doesn't
pass, you can insert sh for interactive debug as below

  -----
  #!/bin/sh
  # description: sample test case

  good-command
  suspicious-wrong-command
  sh # <- add this for interactive debug
  -----
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

tools/testing/selftests/ftrace/ftracetest

@@ -60,11 +60,21 @@ parse_opts() { # opts
       shift 1
     ;;
     --verbose|-v|-vv|-vvv)
+      if [ $VERBOSE -eq -1 ]; then
+	usage "--console can not use with --verbose"
+      fi
       VERBOSE=$((VERBOSE + 1))
       [ $1 = '-vv' ] && VERBOSE=$((VERBOSE + 1))
       [ $1 = '-vvv' ] && VERBOSE=$((VERBOSE + 2))
       shift 1
     ;;
+    --console)
+      if [ $VERBOSE -ne 0 ]; then
+	usage "--console can not use with --verbose"
+      fi
+      VERBOSE=-1
+      shift 1
+    ;;
     --debug|-d)
       DEBUG=1
       shift 1
@@ -283,7 +293,9 @@ run_test() { # testfile
   testcase $1
   echo "execute$INSTANCE: "$1 > $testlog
   SIG_RESULT=0
-  if [ -z "$LOG_FILE" ]; then
+  if [ $VERBOSE -eq -1 ]; then
+    __run_test $1
+  elif [ -z "$LOG_FILE" ]; then
     __run_test $1 2>&1
   elif [ $VERBOSE -ge 3 ]; then
     __run_test $1 | tee -a $testlog 2>&1