Fix unhandled exception in mysql-test-run.pl, creating a dir that already exist

mysql-test/lib/mtr_process.pl:
  Remove junk code/comments
  Moved the creation of var/log out of function mtr_kill_leftovers
mysql-test/mysql-test-run.pl:
  Rename 'kill_running_server' to more appropriate name 'kill_running_servers'
  If no var/log dir exists when mtr_kill_leftovers is started it should be created
  Remove "unless" syntax, too perlish
  Fix typo

mysql-test/lib/mtr_process.pl

@@ -339,19 +339,6 @@ sub mtr_kill_leftovers () {
   mtr_report("Killing Possible Leftover Processes");
   mtr_debug("mtr_kill_leftovers(): started.");
 
-  mkpath("$::opt_vardir/log"); # Needed for mysqladmin log
-
-  # Stop or kill Instance Manager and all its children. If we failed to do
-  # that, we can only abort -- there is nothing left to do.
-
-#  mtr_error("Failed to stop Instance Manager.")
-#    unless mtr_im_stop($::instance_manager);
-
-  # Start shutdown of masters and slaves. Don't touch IM-managed mysqld
-  # instances -- they should be stopped by mtr_im_stop().
-
-  mtr_debug("Shutting down mysqld-instances...");
-
   my @kill_pids;
   my %admin_pids;
 

mysql-test/mysql-test-run.pl

@@ -310,7 +310,7 @@ sub command_line_setup ();
 sub datadir_setup ();
 sub executable_setup ();
 sub environment_setup ();
-sub kill_running_server ();
+sub kill_running_servers ();
 sub cleanup_stale_files ();
 sub check_ssl_support ($);
 sub check_running_as_root();
@@ -1802,7 +1802,7 @@ sub handle_int_signal () {
 #
 ##############################################################################
 
-sub kill_running_server () {
+sub kill_running_servers () {
 
   if ( $opt_fast or $glob_use_embedded_server )
   {
@@ -1820,6 +1820,13 @@ sub kill_running_server () {
     # started from this run of the script, this is terminating
     # leftovers from previous runs.
 
+    if ( ! -d $opt_vardir )
+    {
+      # The "var" dir does not exist already
+      # the processes that mtr_kill_leftovers start will write
+      # their log files to var/log so it should be created
+      mkpath("$opt_vardir/log");
+    }
     mtr_kill_leftovers();
    }
 }
@@ -2416,9 +2423,9 @@ sub initialize_servers () {
 
   if ( ! $glob_use_running_server )
   {
-    kill_running_server();
+    kill_running_servers();
 
-    unless ( $opt_start_dirty )
+    if ( ! $opt_start_dirty )
     {
       cleanup_stale_files();
       mysql_install_db();
@@ -3782,7 +3789,7 @@ sub run_testcase_stop_servers($$$) {
 #
 # run_testcase_start_servers
 #
-# Start the servers neede by this test case
+# Start the servers needed by this test case
 #
 # RETURN
 #  0 OK