perf report: Support switching data w/ and w/o callchains

perf report: Support switching data w/ and w/o callchains

The symbol_conf.use_callchain should be reset when switching to new data
file, otherwise report__setup_sample_type() will show an error message
that it enabled callchains but no callchain data.  The function also
will turn on the callchains if the data has PERF_SAMPLE_CALLCHAIN so I
think it's ok to reset symbol_conf.use_callchain here.

Link: https://lore.kernel.org/r/20250211060745.294289-2-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>