Fix compiling with gcc [4.2.1] after r287797 when MK_HESOID == no and

MK_NIS == no by converting `i` back to an int, and instead cast the loop
comparison to `int`

The loop comparison is iterating the len(ns_dtab)-1, because
the last element is the sentinel tuple { NULL, NULL, NULL, }, so when
both HESOID and NIS are off, len(ns_dtab)-1 == 1 - 1 == 0, and the loop
is skipped because the expression is tautologically false

While here, convert `(sizeof(x) / sizeof(x[0]))` to `nitems(x)`

Tested with: clang 3.7.0, gcc 4.2.1, and gcc 4.9.4 [*] with MK_NIS={no,yes}
             and by running bash -lc 'id -u && id -g && id'

* gcc 4.9.4 needs another patch in order for the compile to succeed
  with -Werror with lib/libc/gen/getgrent.c

Reported by: jhibbits

0 files changed, 0 insertions, 0 deletions