perf disassemble: Move check for kallsyms + !kcore

We don't need to do all that filename logic to then just have to test
something unrelated and bail out, move it to the start of the function.

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-lk1v4srtsktonnyp6t1o0uhx@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/annotate.c

@@ -1165,11 +1165,10 @@ int symbol__strerror_disassemble(struct symbol *sym __maybe_unused, struct map *
 int symbol__disassemble(struct symbol *sym, struct map *map, size_t privsize)
 {
 	struct dso *dso = map->dso;
-	char *filename = dso__build_id_filename(dso, NULL, 0);
+	char *filename;
 	bool free_filename = true;
 	char command[PATH_MAX * 2];
 	FILE *file;
-	int err = 0;
 	char symfs_filename[PATH_MAX];
 	struct kcore_extract kce;
 	bool delete_extract = false;
@@ -1177,7 +1176,13 @@ int symbol__disassemble(struct symbol *sym, struct map *map, size_t privsize)
 	int lineno = 0;
 	int nline;
 	pid_t pid;
+	int err = SYMBOL_ANNOTATE_ERRNO__NO_VMLINUX;
+
+	if (dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
+	    !dso__is_kcore(dso))
+		goto out;
 
+	filename = dso__build_id_filename(dso, NULL, 0);
 	if (filename)
 		symbol__join_symfs(symfs_filename, filename);
 
@@ -1201,12 +1206,6 @@ int symbol__disassemble(struct symbol *sym, struct map *map, size_t privsize)
 		free_filename = false;
 	}
 
-	if (dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
-	    !dso__is_kcore(dso)) {
-		err = SYMBOL_ANNOTATE_ERRNO__NO_VMLINUX;
-		goto out_free_filename;
-	}
-
 	pr_debug("%s: filename=%s, sym=%s, start=%#" PRIx64 ", end=%#" PRIx64 "\n", __func__,
 		 filename, sym->name, map->unmap_ip(map, sym->start),
 		 map->unmap_ip(map, sym->end));
@@ -1338,6 +1337,7 @@ int symbol__disassemble(struct symbol *sym, struct map *map, size_t privsize)
 		kcore_extract__delete(&kce);
 	if (free_filename)
 		free(filename);
+out:
 	return err;
 
 out_close_stdout: