Remove stale TODO.

It was fixed in https://r.android.com/1621159.

#codehealth

Test: n/a - comment change only
Bug: 142944043
Change-Id: I272d89581578be2cd014dcf9b14dfa935eab4fac
diff --git a/sigchainlib/sigchain.h b/sigchainlib/sigchain.h
index 13ec85d..9c24a6f 100644
--- a/sigchainlib/sigchain.h
+++ b/sigchainlib/sigchain.h
@@ -17,10 +17,6 @@
 #ifndef ART_SIGCHAINLIB_SIGCHAIN_H_
 #define ART_SIGCHAINLIB_SIGCHAIN_H_
 
-// TODO(b/142944043): Symbol changes here currently need to be reflected in
-// version scripts in frameworks/base/cmds/app_process. The plan is to convert
-// libsigchain to a shared lib to get rid of them.
-
 #include <signal.h>
 #include <stdint.h>