* src/groupdel.c: Use a bool when possible instead of int

	* src/groupdel.c: Use a bool when possible instead of int
	integers.
	* src/groupdel.c: Avoid implicit conversion of pointers / integers to
	booleans.
	* src/groupdel.c: Avoid assignments in comparisons.
	* src/groupdel.c: Ignore the return value of pam_end() before
	exiting.
	* src/groupdel.c: Ignore return value of setlocale(),
	bindtextdomain(), and textdomain().