[hackers] [ubase] Only check errno if getpwnam() fails || sin

[git]

commit 6af24e35f954e21bdafd3d0e0f7fb76e92ac93bd
Author: sin <s...@2f30.org>
Date:   Mon Aug 18 21:49:22 2014 +0100

    Only check errno if getpwnam() fails

diff --git a/login.c b/login.c
index 51b1f77..fde7ad3 100644
--- a/login.c
+++ b/login.c
@@ -74,13 +74,15 @@ main(int argc, char *argv[])
        if (isatty(STDIN_FILENO) == 0)
                eprintf("stdin is not a tty
");
 
-       errno = 0;
        user = argv[0];
+       errno = 0;
        pw = getpwnam(user);
-       if (errno)
-               eprintf("getpwnam: %s:", user);
-       else if (!pw)
-               eprintf("who are you?
");
+       if (!pw) {
+               if (errno)
+                       eprintf("getpwnam: %s:", user);
+               else
+                       eprintf("who are you?
");
+       }
 
        uid = pw->pw_uid;
        gid = pw->pw_gid;