perf symbols: No need to check if sym->name is NULL

As it is an array, so will always evaluate to 'true', as reported by
clang:

  builtin-sched.c:2070:19: error: address of array 'sym->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
                  if (sym && sym->name) {
                          ~~ ~~~~~^~~~
  1 warning generated.

So just ditch all those useless checks.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ydpm927col06paixb775jjx5@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-kmem.c

@@ -1065,7 +1065,7 @@ static void __print_page_alloc_result(struct perf_session *session, int n_lines)
 
 		data = rb_entry(next, struct page_stat, node);
 		sym = machine__find_kernel_function(machine, data->callsite, &map);
-		if (sym && sym->name)
+		if (sym)
 			caller = sym->name;
 		else
 			scnprintf(buf, sizeof(buf), "%"PRIx64, data->callsite);
@@ -1107,7 +1107,7 @@ static void __print_page_caller_result(struct perf_session *session, int n_lines
 
 		data = rb_entry(next, struct page_stat, node);
 		sym = machine__find_kernel_function(machine, data->callsite, &map);
-		if (sym && sym->name)
+		if (sym)
 			caller = sym->name;
 		else
 			scnprintf(buf, sizeof(buf), "%"PRIx64, data->callsite);

tools/perf/builtin-sched.c

@@ -2067,7 +2067,7 @@ static void save_task_callchain(struct perf_sched *sched,
 			break;
 
 		sym = node->sym;
-		if (sym && sym->name) {
+		if (sym) {
 			if (!strcmp(sym->name, "schedule") ||
 			    !strcmp(sym->name, "__schedule") ||
 			    !strcmp(sym->name, "preempt_schedule"))

tools/perf/util/evsel_fprintf.c

@@ -168,7 +168,6 @@ int sample__fprintf_callchain(struct perf_sample *sample, int left_alignment,
 
 			if (symbol_conf.bt_stop_list &&
 			    node->sym &&
-			    node->sym->name &&
 			    strlist__has_entry(symbol_conf.bt_stop_list,
 					       node->sym->name)) {
 				break;

tools/perf/util/machine.c

@@ -1565,7 +1565,7 @@ int machine__process_event(struct machine *machine, union perf_event *event,
 
 static bool symbol__match_regex(struct symbol *sym, regex_t *regex)
 {
-	if (sym->name && !regexec(regex, sym->name, 0, NULL, 0))
+	if (!regexec(regex, sym->name, 0, NULL, 0))
 		return 1;
 	return 0;
 }

tools/perf/util/symbol_fprintf.c

@@ -21,7 +21,7 @@ size_t __symbol__fprintf_symname_offs(const struct symbol *sym,
 	unsigned long offset;
 	size_t length;
 
-	if (sym && sym->name) {
+	if (sym) {
 		length = fprintf(fp, "%s", sym->name);
 		if (al && print_offsets) {
 			if (al->addr < sym->end)