perf tests: Skip data symbol test if buf1 symbol is missing

perf data symbol test depends on finding symbol buf1 in perf, and fails if
perf has been stripped and no debug object is available. In that case, skip
the test instead.

Example:

Before:

$ strip tools/perf/perf
$ tools/perf/perf buildid-cache -p `realpath tools/perf/perf`
$ tools/perf/perf test -v 'data symbol'
113: Test data symbol :
--- start ---
test child forked, pid 125646
Recording workload...
[ perf record: Woken up 3 times to write data ]
[ perf record: Captured and wrote 0.577 MB /tmp/__perf_test.perf.data.Jhbdp (7794 samples) ]
Cleaning up files...
test child finished with -1
---- end ----
Test data symbol: FAILED!

After:

$ tools/perf/perf test -v 'data symbol'
113: Test data symbol :
--- start ---
test child forked, pid 125747
perf does not have symbol 'buf1'
perf is missing symbols - skipping test
test child finished with -2
---- end ----
Test data symbol: Skip

Signed-off-by: Adrian Hunter <[e-mail]>
Acked-by: Ian Rogers <[e-mail]>
Cc: German Gomez <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Leo Yan <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/shell/test_data_symbol.sh

···
 # shellcheck source=lib/waiting.sh
 . "${shelldir}"/lib/waiting.sh
 
+# shellcheck source=lib/perf_has_symbol.sh
+. "${shelldir}"/lib/perf_has_symbol.sh
+
 skip_if_no_mem_event() {
 	perf mem record -e list 2>&1 | grep -E -q 'available' && return 0
 	return 2
 }
 
 skip_if_no_mem_event || exit 2
+
+skip_test_missing_symbol buf1
 
 TEST_PROGRAM="perf test -w datasym"
 PERF_DATA=$(mktemp /tmp/__perf_test.perf.data.XXXXX)