Tie-File/t/09_gen_rs.t: close before reopening

Opening for write a file you've already got open for write is
generally a bad idea and on VMS is a hard error, causing this
test to fail.  So clean up in between tests.

Author: craigberry

dist/Tie-File/t/09_gen_rs.t

@@ -111,6 +111,7 @@ if (setup_badly_terminated_file(3)) {
   $N++;
   push @a, "next";
   check_contents($badrec, "next");
+  undef $o; untie @a;
 }
 # (51-52)
 if (setup_badly_terminated_file(2)) {
@@ -119,6 +120,7 @@ if (setup_badly_terminated_file(2)) {
     or die "Couldn't tie file: $!";
   splice @a, 1, 0, "x", "y";
   check_contents($badrec, "x", "y");
+  undef $o; untie @a;
 }
 # (53-56)
 if (setup_badly_terminated_file(4)) {
@@ -133,6 +135,7 @@ if (setup_badly_terminated_file(4)) {
     : "not ok $N \# expected <$badrec>, got <$r[0]>\n";
   $N++;
   check_contents("x", "y");
+  undef $o; untie @a;
 }
 
 # (57-58) 20020402 The modification would have failed if $\ were set wrong.
@@ -145,6 +148,7 @@ if (setup_badly_terminated_file(2)) {
     my $z = $a[0];
   }
   check_contents($badrec);
+  undef $o; untie @a;
 }
 
 # (59) 20030527 Tom Christiansen pointed out that FETCH returns the wrong
@@ -162,6 +166,7 @@ if (setup_badly_terminated_file(1)) {
   print $z eq "hello" ? "ok $N\n" : 
       "not ok $N \# got $z, expected hello\n";
   $N++;
+  untie @a;
 }
 
 sub setup_badly_terminated_file {