tools lib traceevent: Add '~' operation within arg_num_eval()

When evaluating values for print flags, if the value included a '~'
operator, the parsing would fail. This broke kmalloc's parsing of:

__print_flags(REC->gfp_flags, "|", {(unsigned
long)((((((( gfp_t)(0x400000u|0x2000000u)) | (( gfp_t)0x40u) |
(( gfp_t)0x80u) | (( gfp_t)0x20000u)) | (( gfp_t)0x02u)) |
(( gfp_t)0x08u)) | (( gfp_t)0x4000u) | (( gfp_t)0x10000u) |
(( gfp_t)0x1000u) | (( gfp_t)0x200u)) & ~(( gfp_t)0x2000000u))
                                        ^
                                        |
                                      here

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: David Ahern <dsahern@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20160226181328.22f47129@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/event-parse.c

@@ -2398,6 +2398,12 @@ static int arg_num_eval(struct print_arg *arg, long long *val)
 				break;
 			*val = left + right;
 			break;
+		case '~':
+			ret = arg_num_eval(arg->op.right, &right);
+			if (!ret)
+				break;
+			*val = ~right;
+			break;
 		default:
 			do_warning("unknown op '%s'", arg->op.op);
 			ret = 0;