hash.c: replace some unsigned long with unsigned int

hash.c: replace some unsigned long with unsigned int

	* hash.c (higher_prime_number): Use uint32_t param, return value,
	tables and variables.
	(bfd_default_hash_table_size): Make it an unsigned int.
	(bfd_hash_set_default_size): Use unsigned int param and return.
	* bfd-in.h (bfd_hash_set_default_size): Update prototype.
	* bfd-in2.h: Regenerate.