Use ENTRY_PRIVATE in __bionic_clone assembler.

Bug: N/A
Test: bionic tests
Change-Id: Ic651d628be009487a36d0b2e5bcf900b981b1ef9
diff --git a/libc/arch-arm64/bionic/__bionic_clone.S b/libc/arch-arm64/bionic/__bionic_clone.S
index 27e44e7..c3ff0e5 100644
--- a/libc/arch-arm64/bionic/__bionic_clone.S
+++ b/libc/arch-arm64/bionic/__bionic_clone.S
@@ -30,7 +30,7 @@
 
 // pid_t __bionic_clone(int flags, void* child_stack, pid_t* parent_tid, void* tls, pid_t* child_tid, int (*fn)(void*), void* arg);
 
-ENTRY(__bionic_clone)
+ENTRY_PRIVATE(__bionic_clone)
     # Push 'fn' and 'arg' onto the child stack.
     stp     x5, x6, [x1, #-16]!
 
@@ -57,4 +57,3 @@
     ldp     x0, x1, [sp], #16
     b       __start_thread
 END(__bionic_clone)
-.hidden __bionic_clone