Another round of inclusion fixes for _ISOMAC testsuite.

	* stdio-common/bug25.c: Include stdlib.h.
	* support/tst-support_format_dns_packet.c: Include stdio.h,
	stdlib.h, and string.h.
	* support/tst-support_record_failure.c: Include string.h.
	* support/tst-support_record_failure-2.sh: Adjust line number
	expectations and correct a typo in an error message.