perf intel-pt: Fix unassigned instruction op (discovered by MemorySanitizer)

MemorySanitizer discovered instances where the instruction op value was
not assigned.:

WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x5581c00a76b3 in intel_pt_sample_flags tools/perf/util/intel-pt.c:1527:17
Uninitialized value was stored to memory at
#0 0x5581c005ddf8 in intel_pt_walk_insn tools/perf/util/intel-pt-decoder/intel-pt-decoder.c:1256:25

The op value is used to set branch flags for branch instructions
encountered when walking the code, so fix by setting op to
INTEL_PT_OP_OTHER in other cases.

Fixes: 4c761d805bb2d2ea ("perf intel-pt: Fix intel_pt_fup_event() assumptions about setting state type")
Reported-by: Ian Rogers <[e-mail]>
Signed-off-by: Adrian Hunter <[e-mail]>
Tested-by: Ian Rogers <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Closes: https://lore.kernel.org/linux-perf-users/[e-mail]/
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/intel-pt-decoder/intel-pt-decoder.c

···
 	bool ret = false;
 
 	decoder->state.type &= ~INTEL_PT_BRANCH;
+	decoder->state.insn_op = INTEL_PT_OP_OTHER;
+	decoder->state.insn_len = 0;
 
 	if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
 		bool ip = decoder->set_fup_cfe_ip;

tools/perf/util/intel-pt.c

···
 
 	addr_location__init(&al);
 	intel_pt_insn->length = 0;
+	intel_pt_insn->op = INTEL_PT_OP_OTHER;
 
 	if (to_ip && *ip == to_ip)
 		goto out_no_cache;
···
 
 			if (to_ip && *ip == to_ip) {
 				intel_pt_insn->length = 0;
+				intel_pt_insn->op = INTEL_PT_OP_OTHER;
 				goto out_no_cache;
 			}