Remove optimized code for bzero, which was removed from POSIX in 2008.

I'll come back for the last bcopy remnant...

Bug: http://b/26407170
Change-Id: Iabfeb95fc8a4b4b3992e3cc209ec5221040e7c26
diff --git a/libc/arch-arm/denver/bionic/memset.S b/libc/arch-arm/denver/bionic/memset.S
index 8d79e5b..1b0152a 100644
--- a/libc/arch-arm/denver/bionic/memset.S
+++ b/libc/arch-arm/denver/bionic/memset.S
@@ -42,7 +42,7 @@
 
 ENTRY(__memset_chk)
         cmp         r2, r3
-        bls         .L_done
+        bls         memset
 
         // Preserve lr for backtrace.
         push        {lr}
@@ -52,13 +52,6 @@
         bl          __memset_chk_fail
 END(__memset_chk)
 
-ENTRY(bzero)
-        mov         r2, r1
-        mov         r1, #0
-.L_done:
-        // Fall through to memset...
-END(bzero)
-
 ENTRY(memset)
         pldw        [r0]
         mov         r3, r0