Fix debuggerd's use of readdir_r(3).

Change-Id: I1b178af054cefebfb774320e4b4699d6dc8bbb01
diff --git a/debuggerd/tombstone.c b/debuggerd/tombstone.c
index 52223da..47a1bf5 100644
--- a/debuggerd/tombstone.c
+++ b/debuggerd/tombstone.c
@@ -405,9 +405,8 @@
     }
 
     bool detach_failed = false;
-    struct dirent debuf;
-    struct dirent *de;
-    while (!readdir_r(d, &debuf, &de) && de) {
+    struct dirent* de;
+    while ((de = readdir(d)) != NULL) {
         /* Ignore "." and ".." */
         if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) {
             continue;