Make chdir failures visible

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/setup.c b/setup.c
index 78a8041..833ced2 100644
--- a/setup.c
+++ b/setup.c
@@ -470,7 +470,8 @@
 			}
 			die("Not a git repository");
 		}
-		chdir("..");
+		if (chdir(".."))
+			die("Cannot change to %s/..: %s", cwd, strerror(errno));
 	}
 
 	inside_git_dir = 0;