mysqlhotcopy tests fixed.

The 'mysqlhotcopy' tool gets into bin/ directory after the installation
from the scripts/.
So check for it in that in the mysql-test-run.pl.

per-file comments:
  mysql-test/mysql-test-run.pl
Check the bin/ for mysqlhotcopy presence.

mysql-test/mysql-test-run.pl

@@ -2155,9 +2155,8 @@ sub environment_setup {
   # mysqlhotcopy
   # ----------------------------------------------------
   my $mysqlhotcopy=
-    mtr_pl_maybe_exists("$bindir/scripts/mysqlhotcopy");
-  # Since mysqltest interprets the real path as "false" in an if,
-  # use 1 ("true") to indicate "not exists" so it can be tested for
+    mtr_pl_maybe_exists("$bindir/scripts/mysqlhotcopy") ||
+    mtr_pl_maybe_exists("$path_client_bindir/mysqlhotcopy");
   if ($mysqlhotcopy)
   {
     $ENV{'MYSQLHOTCOPY'}= $mysqlhotcopy;