Git::SVN: rename private path field

All users of $gs->{path} should have been converted to use the
accessor by now.  Check our work by renaming the underlying variable
to break callers that try to use it directly.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>

perl/Git/SVN.pm

@@ -2331,11 +2331,11 @@ sub path {
 
 	if (@_) {
 		my $path = shift;
-		$self->{path} = canonicalize_path($path);
+		$self->{_path} = canonicalize_path($path);
 		return;
 	}
 
-	return $self->{path};
+	return $self->{_path};
 }
 
 sub url {