perf tests shell: Skip trace+probe_vfs_getname.sh if built without trace support

If perf was built without trace support, the trace+probe_vfs_getname.sh
'perf test' entry fails:

  # perf trace -h
  perf: 'trace' is not a perf-command. See 'perf --help'

  # perf test 64
  64: Check open filename arg using perf trace + vfs_getname: FAILED!

Check trace support, so that we'll skip the test in that case:

  # perf test 64
  64: Check open filename arg using perf trace + vfs_getname: Skip
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190215134253.11454-1-tt.rantala@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/lib/probe.sh

@@ -4,3 +4,8 @@ skip_if_no_perf_probe() {
 	perf probe 2>&1 | grep -q 'is not a perf-command' && return 2
 	return 0
 }
+
+skip_if_no_perf_trace() {
+	perf trace -h 2>&1 | grep -q -e 'is not a perf-command' -e 'trace command not available' && return 2
+	return 0
+}

tools/perf/tests/shell/trace+probe_vfs_getname.sh

@@ -12,6 +12,7 @@
 . $(dirname $0)/lib/probe.sh
 
 skip_if_no_perf_probe || exit 2
+skip_if_no_perf_trace || exit 2
 
 . $(dirname $0)/lib/probe_vfs_getname.sh