Use new semantics of is_bare/inside_git_dir/inside_work_tree

Up to now to check for a working tree this was used:
	!is_bare && !inside_git_dir
(the check for bare is redundant because is_inside_git_dir
returned already 1 for bare repositories).
Now the check is:
	inside_work_tree && !inside_git_dir

Signed-off-by: Matthias Lederhofer <matled@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/git-svn.perl b/git-svn.perl
index e3a5cbb..886b898 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -594,7 +594,7 @@
 	my $index = $ENV{GIT_INDEX_FILE} || "$ENV{GIT_DIR}/index";
 	return if -f $index;
 
-	return if command_oneline(qw/rev-parse --is-bare-repository/) eq 'true';
+	return if command_oneline(qw/rev-parse --is-inside-work-tree/) eq 'false';
 	return if command_oneline(qw/rev-parse --is-inside-git-dir/) eq 'true';
 	command_noisy(qw/read-tree -m -u -v HEAD HEAD/);
 	print STDERR "Checked out HEAD:\n  ",