ftracetest: Convert exit -1 to exit $FAIL

POSIX says that exit takes an unsigned integer between 0 and 255, so
using -1 doesn't work on POSIX shells.

There is already a well-defined failure code, $FAIL (1), so use that.

Signed-off-by: Michael Ellerman <[e-mail]>
Acked-by: Steven Rostedt <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/ftrace/test.d/00basic/basic4.tc

···
 # description: Basic event tracing check
 test -f available_events -a -f set_event -a -d events
 # check scheduler events are available
-grep -q sched available_events && exit 0 || exit -1
+grep -q sched available_events && exit 0 || exit $FAIL

tools/testing/selftests/ftrace/test.d/event/event-enable.tc

···
 fail() { #msg
     do_reset
     echo $1
-    exit -1
+    exit $FAIL
 }
 
 if [ ! -f set_event -o ! -d events/sched ]; then

tools/testing/selftests/ftrace/test.d/event/subsystem-enable.tc

···
 fail() { #msg
     do_reset
     echo $1
-    exit -1
+    exit $FAIL
 }
 
 if [ ! -f set_event -o ! -d events/sched ]; then

tools/testing/selftests/ftrace/test.d/event/toplevel-enable.tc

···
 fail() { #msg
     do_reset
     echo $1
-    exit -1
+    exit $FAIL
 }
 
 if [ ! -f available_events -o ! -f set_event -o ! -d events ]; then

tools/testing/selftests/ftrace/test.d/ftrace/fgraph-filter-stack.tc

···
 fail() { # msg
     do_reset
     echo $1
-    exit -1
+    exit $FAIL
 }
 
 disable_tracing

tools/testing/selftests/ftrace/test.d/ftrace/fgraph-filter.tc

···
 fail() { # msg
     do_reset
     echo $1
-    exit -1
+    exit $FAIL
 }
 
 disable_tracing

tools/testing/selftests/ftrace/test.d/ftrace/func_profiler.tc

···
     reset_tracer
     echo > set_ftrace_filter
     echo $1
-    exit -1
+    exit $FAIL
 }
 
 echo "Testing function tracer with profiler:"