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)
Signed-off-by: chenyuan <[email protected]>

Author: chenyuan0001

tools/bpf/bpftool/main.c

@@ -164,6 +164,7 @@ static int do_version(int argc, char **argv)
 		jsonw_end_object(json_wtr);	/* features */
 
 		jsonw_end_object(json_wtr);	/* root object */
+		jsonw_destroy(&json_wtr);
 	} else {
 		unsigned int nb_features = 0;