[NaCl SDK] Make the SDK examples buildable as a packaged app.

native_client_sdk/src/libraries/nacl_io/mount_node.cc

Index: native_client_sdk/src/libraries/nacl_io/mount_node.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/mount_node.cc b/native_client_sdk/src/libraries/nacl_io/mount_node.cc
index d31b99fc27251afb45f9774128a2030fa1d27ebd..823a138d682a76831fcecca4b72297f7c258b7ba 100644
--- a/native_client_sdk/src/libraries/nacl_io/mount_node.cc
+++ b/native_client_sdk/src/libraries/nacl_io/mount_node.cc
@@ -85,15 +85,15 @@ void* MountNode::MMap(void* addr, size_t length, int prot, int flags,
   void* new_addr = addr;
   int err = _real_mmap(&new_addr, length, prot | PROT_WRITE, flags |
                        MAP_ANONYMOUS, -1, 0);
-  if (addr == MAP_FAILED) {
-    _real_munmap(addr, length);
+  if (new_addr == MAP_FAILED) {
+    _real_munmap(new_addr, length);
     errno = err;
     return MAP_FAILED;
   }
 
-  ssize_t cnt = Read(offset, addr, length);
+  ssize_t cnt = Read(offset, new_addr, length);
   if (cnt == -1) {
-    _real_munmap(addr, length);
+    _real_munmap(new_addr, length);
     errno = ENOSYS;
     return MAP_FAILED;
   }