[PATCH] setup: update the right file in multiple checkouts

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

This code is introduced in 23af91d (prune: strategies for linked
checkouts - 2014-11-30), and it's supposed to implement this rule from
that commit's message:

 - linked checkouts are supposed to keep its location in $R/gitdir up
   to date. The use case is auto fixup after a manual checkout move.

Note the name, "$R/gitdir", not "$R/gitfile". Correct the path to be
updated accordingly.

While at there, make sure I/O errors are not silently dropped.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 The code was right in v2 [1] and became "gitfile" since v3 [2]. I
 need to reconsider my code quality after this :(

 [1] http://article.gmane.org/gmane.comp.version-control.git/239299
 [2] http://article.gmane.org/gmane.comp.version-control.git/242325

 setup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/setup.c b/setup.c
index 5f9f07d..64bf2b4 100644
--- a/setup.c
+++ b/setup.c
@@ -402,9 +402,9 @@ static void update_linked_gitdir(const char *gitfile, const char *gitdir)
 	struct strbuf path = STRBUF_INIT;
 	struct stat st;
 
-	strbuf_addf(&path, "%s/gitfile", gitdir);
+	strbuf_addf(&path, "%s/gitdir", gitdir);
 	if (stat(path.buf, &st) || st.st_mtime + 24 * 3600 < time(NULL))
-		write_file(path.buf, 0, "%s\n", gitfile);
+		write_file(path.buf, 1, "%s\n", gitfile);
 	strbuf_release(&path);
 }
 
-- 
2.3.0.rc1.137.g477eb31