tools/mm: free the allocated memory

The comm_str memory needs to be freed if the search_pattern function call
fails in get_comm

[akpm@linux-foundation.org: fix whitespace]
Link: https://lkml.kernel.org/r/20241022012526.7597-1-liujing@cmss.chinamobile.com
Signed-off-by: Liu Jing <liujing@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/mm/page_owner_sort.c

@@ -377,6 +377,7 @@ static char *get_comm(char *buf)
 	if (errno != 0) {
 		if (debug_on)
 			fprintf(stderr, "wrong comm in follow buf:\n%s\n", buf);
+		free(comm_str);
 		return NULL;
 	}