perf test annotate: Use --percent-limit rather than head to reduce output

perf test annotate: Use --percent-limit rather than head to reduce output

The annotate test was sped up by Thomas Richter
<tmricht@linux.ibm.com> in commit
658a8805cb60 ("perf test: Speed up test case 70 annotate basic tests")
by reducing the annotate output using head. This causes flakes on
hybrid machines where the first event dumped may not have the samples
for the test within it. Rather than reduce the output using `head`
switch to `--percent-limit 10` which will stop annotate dumping
functions that have an overhead of less than 10%, the noploop program
should be using more.

Add the missing objdump option for the pipe mode version of the
objdump with a command test.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20250628015832.1271229-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>