perf test: Record only user callchains on the "Check Arm64 callgraphs are complete...

perf test: Record only user callchains on the "Check Arm64 callgraphs are complete in fp mode" test

The testcase 'Check Arm64 callgraphs are complete in fp mode' wants to
see the following output:

    610 leaf
    62f parent
    648 main

However, without excluding kernel callchains, the output might look like:

	ffffc2ff40ef1b5c arch_local_irq_enable
	ffffc2ff419d032c __schedule
	ffffc2ff419d06c0 schedule
	ffffc2ff40e4da30 do_notify_resume
	ffffc2ff40e421b0 work_pending
	             610 leaf
	             62f parent
	             648 main

Adding '--user-callchains' leaves only the wanted symbols in the chain.

Fixes: cd6382d82752737e ("perf test arm64: Test unwinding using fame-pointer (fp) mode")
Suggested-by: German Gomez <german.gomez@arm.com>
Reviewed-by: German Gomez <german.gomez@arm.com>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Michael Petlan <mpetlan@redhat.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220614105207.26223-1-mpetlan@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>