Don't go into dotted directories when copying Makefile.in to Makefile

Reviewed-by: NRich Salz <rsalz@openssl.org>

Configure

@@ -1297,7 +1297,12 @@ foreach my $alg ( 'bn' ) {
 # Copy all Makefile.in to Makefile (except top-level)
 use File::Find;
 use IO::File;
-find(sub {
+find(
+    {
+        preprocess => sub {
+            grep(!/^\./, @_);
+        },
+        wanted => sub {
             return if ($_ ne "Makefile.in" || $File::Find::dir eq ".");
             my $in = IO::File->new($_, "r") or
                 die sprintf "Error reading Makefile.in in %s: !$\n",
@@ -1313,7 +1318,9 @@ find(sub {
             $out->close() or
                 die sprintf "Error writing Makefile in %s: !$\n",
                 $File::Find::dir;
-    }, ".");
+        },
+    },
+    ".");
 
 my %builders = (
     unixmake => sub {