Fix aarch64 (64-bit ARM) guard on chacha_vec_arm.S.

Change-Id: Ia3632639daa8655ea5e2f81ba2a5163949f522b2
Reviewed-on: https://boringssl-review.googlesource.com/6110
Reviewed-by: Adam Langley <alangley@gmail.com>

crypto/chacha/chacha_vec_arm.S

diff --git a/crypto/chacha/chacha_vec_arm.S b/crypto/chacha/chacha_vec_arm.S
index 0f82627..dfd596c 100644
--- a/crypto/chacha/chacha_vec_arm.S
+++ b/crypto/chacha/chacha_vec_arm.S
@@ -23,7 +23,7 @@
 #     /opt/gcc-linaro-4.9-2014.11-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc -O3 -mcpu=cortex-a8 -mfpu=neon -fpic -DASM_GEN -I ../../include -S chacha_vec.c -o -
 
 #if !defined(OPENSSL_NO_ASM)
-#if defined(__arm__) || defined(__aarch64__)
+#if defined(__arm__)
 
 	.syntax unified
 	.cpu cortex-a8
@@ -1424,5 +1424,5 @@
 	.ident	"GCC: (Linaro GCC 2014.11) 4.9.3 20141031 (prerelease)"
 	.section	.note.GNU-stack,"",%progbits
 
-#endif  /* __arm__ || __aarch64__ */
+#endif  /* __arm__ */
 #endif  /* !OPENSSL_NO_ASM */

crypto/chacha/chacha_vec_arm_generate.go

diff --git a/crypto/chacha/chacha_vec_arm_generate.go b/crypto/chacha/chacha_vec_arm_generate.go
index b803ef5..82aa847 100644
--- a/crypto/chacha/chacha_vec_arm_generate.go
+++ b/crypto/chacha/chacha_vec_arm_generate.go
@@ -56,7 +56,7 @@
 	output.WriteString(" ")
 	output.WriteString(strings.Join(args, " "))
 	output.WriteString("\n\n#if !defined(OPENSSL_NO_ASM)\n")
-	output.WriteString("#if defined(__arm__) || defined(__aarch64__)\n\n")
+	output.WriteString("#if defined(__arm__)\n\n")
 
 	cmd := exec.Command(compiler, args...)
 	cmd.Stderr = os.Stderr
@@ -148,6 +148,6 @@
 `
 
 const trailer = `
-#endif  /* __arm__ || __aarch64__ */
+#endif  /* __arm__ */
 #endif  /* !OPENSSL_NO_ASM */
 `