cmd_pmc_record() returns status, which still holds the return value of
kevent(), 1, when the EVFILT_TIMER branch jumps to done after the -t
time limit has elapsed. A timed recording therefore exits with status
1, while one interrupted with SIGINT exits with EX_OK.

Set status to EX_OK in the timer branch. pmc_cli_test and
amd/pmc_frontend_test accepted status 1 to work around this; make them
require 0.

Reported by: llm-postcr
Fixes: a79a051e7d16 ("pmc: pmc record command")
Sponsored by: Advanced Micro Devices, Inc.
Signed-off-by: Osvaldo Janeri Filho <ojanerif@amd.com>

Built pmc(8) with and without this change and ran both on an AMD Zen 4
host running main:

• pmc record -c instructions -t 2 exits 1 without the change and 0 with it. A capture interrupted with SIGINT still exits 0, and an existing output file still exits 71.
• With the updated pmc_cli_test and amd/pmc_frontend_test, pmc_record_then_info and pmc_frontend_ibs fail against the old pmc(8) and pass against the new one.