Rename # vndk tag to # llndk

The APIs that are tagged with # vndk are actually for LLNDK libraries.
Although LLNDK is part of VNDK, calling those APIs 'vndk' has given
users a wrong perception that the APIs don't need to be kept stable
because that's the norm for most of the VNDK libraries that are not
LLNDK.

In order to eliminate the misunderstanding, rename the tag to 'llndk' so
that people introducing new such API will realize what they are signing
themselves up for.

Bug: 143765505
Test: m
Merged-In: I56e49876410bd43723a80d0204a9aef21d20fca9
(cherry picked from commit 3e2cd44aa41855286d71608810d4c81a7bcc83ae)
Change-Id: I56e49876410bd43723a80d0204a9aef21d20fca9
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index a4ab600..8e843af 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1468,10 +1468,10 @@
     __system_properties_init; # apex
 
     # Used by libmemunreachable
-    malloc_backtrace; # apex vndk
-    malloc_disable; # apex vndk
-    malloc_enable; # apex vndk
-    malloc_iterate; # apex vndk
+    malloc_backtrace; # apex llndk
+    malloc_disable; # apex llndk
+    malloc_enable; # apex llndk
+    malloc_iterate; # apex llndk
 
     # Used by libandroid_net
     android_getaddrinfofornet; # apex