Unbreak group operations by reverting previous delta which removed the

assignment of `l' in `gr_update' to the return value of snprintf.  It
claimed to have fixed the case where snprintf returned -1--in fact, it
broke the entire routine.  Not setting `l' here causes fileupdate() to
invariably fail with EINVAL because it does its own check to assert
that the parameter isn't -1.

usr.sbin/pw/grupd.c

@@ -134,7 +134,7 @@ gr_update(struct group * grp, char const * group, int mode)
 	char	       *grbuf = NULL;
 
 	ENDGRENT();
-	snprintf(pfx, sizeof pfx, "%s:", group);
+	l = snprintf(pfx, sizeof pfx, "%s:", group);
 
 	/*
 	 * Update the group file