Add a bunch more missing ENDs to assembler routines.

This isn't everything; I've missed out those x86 files that are

Change-Id: Idb7bb1a68796d6c0b70ea2b5c3300e49da6c62d2
diff --git a/libc/arch-arm/bionic/memset.S b/libc/arch-arm/bionic/memset.S
index 54f74de..102d541 100644
--- a/libc/arch-arm/bionic/memset.S
+++ b/libc/arch-arm/bionic/memset.S
@@ -42,6 +42,7 @@
 ENTRY(bzero)
         mov     r2, r1
         mov     r1, #0
+        // Fall through to memset...
 END(bzero)
 
 ENTRY(memset)