tools: bpftool: maps: close json array on error paths of show

We can't return from the middle of do_show(), because
json_array will not be closed.  Break out of the loop.
Note that the error handling after the loop depends on
errno, so no need to set err.

Fixes: 831a0aaf ("tools: bpftool: add JSON output for `bpftool map *` commands")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/bpf/bpftool/map.c

@@ -523,21 +523,21 @@ static int do_show(int argc, char **argv)
 				break;
 			p_err("can't get next map: %s%s", strerror(errno),
 			      errno == EINVAL ? " -- kernel too old?" : "");
-			return -1;
+			break;
 		}
 
 		fd = bpf_map_get_fd_by_id(id);
 		if (fd < 0) {
 			p_err("can't get map by id (%u): %s",
 			      id, strerror(errno));
-			return -1;
+			break;
 		}
 
 		err = bpf_obj_get_info_by_fd(fd, &info, &len);
 		if (err) {
 			p_err("can't get map info: %s", strerror(errno));
 			close(fd);
-			return -1;
+			break;
 		}
 
 		if (json_output)