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

2 files changed, 9 insertions, 13 deletions

diff --git a/lib/libc/gen/getgrent.c b/lib/libc/gen/getgrent.c
index 31d2af1..0e18bbb 100644
--- a/lib/libc/gen/getgrent.c
+++ b/lib/libc/gen/getgrent.c
@@ -1239,14 +1239,13 @@ compat_setgrent(void *retval, void *mdata, va_list ap)
 	int		 rv, stayopen;
 
 #define set_setent(x, y) do {	 				\
-	unsigned int i;						\
-								\
-	for (i = 0; i < (sizeof(x)/sizeof(x[0])) - 1; i++)	\
+	int i;							\
+	for (i = 0; i < (int)(nitems(x) - 1); i++)		\
 		x[i].mdata = (void *)y;				\
 } while (0)
 
 	rv = compat_getstate(&st);
-	if (rv != 0) 
+	if (rv != 0)
 		return (NS_UNAVAIL);
 	switch ((enum constants)mdata) {
 	case SETGRENT:
@@ -1309,9 +1308,8 @@ compat_group(void *retval, void *mdata, va_list ap)
 	int			 rv, stayopen, *errnop;
 
 #define set_lookup_type(x, y) do { 				\
-	unsigned int i;						\
-								\
-	for (i = 0; i < (sizeof(x)/sizeof(x[0])) - 1; i++)	\
+	int i;							\
+	for (i = 0; i < (int)(nitems(x) - 1); i++)		\
 		x[i].mdata = (void *)y;				\
 } while (0)
 
diff --git a/lib/libc/gen/getpwent.c b/lib/libc/gen/getpwent.c
index 6546f587..8617ecc 100644
--- a/lib/libc/gen/getpwent.c
+++ b/lib/libc/gen/getpwent.c
@@ -1607,10 +1607,9 @@ compat_redispatch(struct compat_state *st, enum nss_lookup_type how,
 		{ NULL, NULL, NULL }
 	};
 	void		*discard;
-	int		 rv, e;
-	unsigned int	 i;
+	int		 e, i, rv;
 
-	for (i = 0; i < sizeof(dtab)/sizeof(dtab[0]) - 1; i++)
+	for (i = 0; i < (int)(nitems(dtab) - 1); i++)
 		dtab[i].mdata = (void *)lookup_how;
 more:
 	pwd_init(pwd);
@@ -1703,9 +1702,8 @@ compat_setpwent(void *retval, void *mdata, va_list ap)
 	int			 rv, stayopen;
 
 #define set_setent(x, y) do {	 				\
-	unsigned int i;						\
-								\
-	for (i = 0; i < (sizeof(x)/sizeof(x[0])) - 1; i++)	\
+	int i;							\
+	for (i = 0; i < (int)(nitems(x) - 1); i++)		\
 		x[i].mdata = (void *)y;				\
 } while (0)