set FD_CLOEXEC properly when O_CLOEXEC is not supported

FD_CLOEXEC only applies to the file descriptor, so it needs to be
manipuluated via F_GETFD/F_SETFD.  F_GETFL/F_SETFL are for file
description flags.

Verified via strace with o_cloexec set to zero.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

sha1_file.c

@@ -1571,14 +1571,14 @@ int git_open_cloexec(const char *name, int flags)
 		fd = open(name, flags | o_cloexec);
 	}
 
-#if defined(F_GETFL) && defined(F_SETFL) && defined(FD_CLOEXEC)
+#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
 	{
 		static int fd_cloexec = FD_CLOEXEC;
 
 		if (!o_cloexec && 0 <= fd && fd_cloexec) {
 			/* Opened w/o O_CLOEXEC?  try with fcntl(2) to add it */
-			int flags = fcntl(fd, F_GETFL);
-			if (fcntl(fd, F_SETFL, flags | fd_cloexec))
+			int flags = fcntl(fd, F_GETFD);
+			if (fcntl(fd, F_SETFD, flags | fd_cloexec))
 				fd_cloexec = 0;
 		}
 	}