ktest: When creating new config, allow the use of ${THIS_DIR}

Typing in a full path when you know that the path exists within
the directory your are running is tedious and unnecessary.

Allow the user to use ${PWD} if they want a dynamic path name
which will be the path that ktest.pl is executed from
or use ${THIS_DIR} which is a variable assigned `pwd` and
the the variable will exist within the config, allowing the user
to change it and affect all other paths using this variable as well
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

tools/testing/ktest/ktest.pl

@@ -158,11 +158,15 @@ EOF
     ;
 $config_help{"BUILD_DIR"} = << "EOF"
  The directory that contains the Linux source code (full path).
+ You can use \${PWD} that will be the path where ktest.pl is run, or use
+ \${THIS_DIR} which is assigned \${PWD} but may be changed later.
 EOF
     ;
 $config_help{"OUTPUT_DIR"} = << "EOF"
  The directory that the objects will be built (full path).
  (can not be same as BUILD_DIR)
+ You can use \${PWD} that will be the path where ktest.pl is run, or use
+ \${THIS_DIR} which is assigned \${PWD} but may be changed later.
 EOF
     ;
 $config_help{"BUILD_TARGET"} = << "EOF"
@@ -282,7 +286,7 @@ sub get_ktest_config {
 		next;
 	    }
 	}
-	$entered_configs{$config} = process_variables($ans);
+	$entered_configs{$config} = ${ans};
 	last;
     }
 }
@@ -3012,6 +3016,17 @@ if (! -f $ktest_config) {
     print OUT << "EOF"
 # Generated by ktest.pl
 #
+
+# PWD is a ktest.pl variable that will result in the process working
+# directory that ktest.pl is executed in.
+
+# THIS_DIR is automatically assigned the PWD of the path that generated
+# the config file. It is best to use this variable when assigning other
+# directory paths within this directory. This allows you to easily
+# move the test cases to other locations or to other machines.
+#
+THIS_DIR := $variable{"PWD"}
+
 # Define each test with TEST_START
 # The config options below it will override the defaults
 TEST_START
@@ -3034,7 +3049,7 @@ if ($#new_configs >= 0) {
     open(OUT, ">>$ktest_config") or die "Can not append to $ktest_config";
     foreach my $config (@new_configs) {
 	print OUT "$config = $entered_configs{$config}\n";
-	$opt{$config} = $entered_configs{$config};
+	$opt{$config} = process_variables($entered_configs{$config});
     }
 }