lib subcmd: Avoid memory leak in exclude_cmds

exclude_cmds will shorten the cmds names array, before doing so free the
removed entry.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: André Almeida <andrealmeid@igalia.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230611233610.953456-1-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/subcmd/help.c

@@ -66,6 +66,7 @@ void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 	while (ci < cmds->cnt && ei < excludes->cnt) {
 		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
 		if (cmp < 0) {
+			zfree(&cmds->names[cj]);
 			cmds->names[cj++] = cmds->names[ci++];
 		} else if (cmp == 0) {
 			ci++;
@@ -75,9 +76,12 @@ void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 		}
 	}
 
-	while (ci < cmds->cnt)
+	while (ci < cmds->cnt) {
+		zfree(&cmds->names[cj]);
 		cmds->names[cj++] = cmds->names[ci++];
-
+	}
+	for (ci = cj; ci < cmds->cnt; ci++)
+		zfree(&cmds->names[ci]);
 	cmds->cnt = cj;
 }