memset_chk into assembly file

Writing an assembly file can reduce several
assembly instructions, and compare it through
the disassembly of this file

Test: make libc
Change-Id: Ifdcc9c76742cc95b2ad9e3c14fac4796c36e12e6
Signed-off-by: caowencheng <caowencheng@eswincomputing.com>
diff --git a/libc/Android.bp b/libc/Android.bp
index 1e65fea..23b381d 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -672,7 +672,6 @@
         },
         riscv64: {
             srcs: [
-                "arch-riscv64/string/memset_chk.c",
                 "upstream-freebsd/lib/libc/string/memcmp.c",
                 "upstream-freebsd/lib/libc/string/memcpy.c",
                 "upstream-freebsd/lib/libc/string/memmove.c",
@@ -825,6 +824,11 @@
                 "arch-arm64/string/__memset_chk.S",
             ],
         },
+        riscv64: {
+            srcs: [
+               "arch-riscv64/string/__memset_chk.S",
+            ],
+        },
     },
 }