bpftool: Fix JSON writer resource leak in version command

When using `bpftool --version -j/-p`, the JSON writer object
created in do_version() was not properly destroyed after use.
This caused a memory leak each time the version command was
executed with JSON output.

Fix: 004b45c (tools: bpftool: provide JSON output for all possible commands)

Suggested-by: Quentin Monnet <[email protected]>
Signed-off-by: Yuan Chen <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Reviewed-by: Quentin Monnet <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

Author: chenyuan0001

tools/bpf/bpftool/main.c

@@ -534,9 +534,9 @@ int main(int argc, char **argv)
 		usage();
 
 	if (version_requested)
-		return do_version(argc, argv);
-
-	ret = cmd_select(commands, argc, argv, do_help);
+		ret = do_version(argc, argv);
+	else
+		ret = cmd_select(commands, argc, argv, do_help);
 
 	if (json_output)
 		jsonw_destroy(&json_wtr);