utent.c: fix a few bugs, and shrink a bit

bug #1:
    static_fd = -1;
    close(static_fd);
DOH!

bug #2:
    if (utmp_fd == -1) {
        __setutent();
    }
    if (utmp_fd == -1) {
        return NULL;
    }
if utmp_fd == -1, we call _setutent().
if __setutent() opens a fd, utmp_fd (a parameter)
wouldn't change, the second check is bogus.
We need to use static_fd instead in second check.
Which makes clear that having utmp_fd parameter
is wrong. See the patch for a complete fix.

Shrink comes from simplifying fcntl(static_fd, F_SETFD, FD_CLOEXEC):

    text           data     bss     dec     hex filename
-    661              8     384    1053     41d libc/misc/utmp/utent.o
+    604              8     384     996     3e4 libc/misc/utmp/utent.o

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

0 files changed, 0 insertions, 0 deletions