Add a directry spec for mcr if there is none

On VMS, the command MCR will assume SYS$SYSTEM: when the first
argument lacks a directory spec.  So for programs in the current
directory, we add [] to tell MCR it is in the current directory.
It's the same as having ./ at the start of a program on Unix so the
shell doesn't start looking along $PATH.
Reviewed-by: NRich Salz <rsalz@openssl.org>

test/testlib/OpenSSL/Test.pm

@@ -675,7 +675,7 @@ sub __fixup_cmd {
     if (defined($ENV{EXE_SHELL})) {
 	$prefix = "$ENV{EXE_SHELL} ";
     } elsif ($^O eq "VMS" ) {	# VMS
-	$prefix = "mcr ";
+	$prefix = ($prog =~ /^[<\[]/ ? "mcr " : "mcr []");
 	$ext = ".exe";
     } elsif ($^O eq "MSWin32") { # Windows
 	$prefix = "";