Remove dependencies on obsolete __ARCH_WANT_SYSCALL_DEPRECATED system calls.

(aarch64 kernels don't have these system calls.)

Change-Id: I6f64075aa412f71520f2df71c3d69b647f91c1ca
diff --git a/libc/bionic/wait.cpp b/libc/bionic/wait.cpp
index 7dbcec2..27453bb 100644
--- a/libc/bionic/wait.cpp
+++ b/libc/bionic/wait.cpp
@@ -44,7 +44,7 @@
 }
 
 int waitid(idtype_t which, id_t id, siginfo_t* info, int options) {
-  /* the system call takes an option struct rusage that we don't need */
+  // The system call takes an optional struct rusage that we don't need.
   return __waitid(which, id, info, options, NULL);
 }