Rename bssl-ffi to bssl-sys

Test: TreeHugger
Change-Id: I7e8e1a73d47e2fbdf81a4d6b51d7d11cea56db35
diff --git a/libs/bssl/src/curve25519.rs b/libs/bssl/src/curve25519.rs
index 499a3d0..4c1c398 100644
--- a/libs/bssl/src/curve25519.rs
+++ b/libs/bssl/src/curve25519.rs
@@ -17,8 +17,8 @@
 use crate::util::check_int_result;
 use bssl_avf_error::{ApiName, Result};
 
-const ED25519_PUBLIC_KEY_LEN: usize = bssl_ffi::ED25519_PUBLIC_KEY_LEN as usize;
-const ED25519_SIGNATURE_LEN: usize = bssl_ffi::ED25519_SIGNATURE_LEN as usize;
+const ED25519_PUBLIC_KEY_LEN: usize = bssl_sys::ED25519_PUBLIC_KEY_LEN as usize;
+const ED25519_SIGNATURE_LEN: usize = bssl_sys::ED25519_SIGNATURE_LEN as usize;
 
 /// Verifies the signature of a message with the given ED25519 public key.
 pub fn ed25519_verify(
@@ -28,7 +28,7 @@
 ) -> Result<()> {
     // SAFETY: The function only reads the parameters within their bounds.
     let ret = unsafe {
-        bssl_ffi::ED25519_verify(
+        bssl_sys::ED25519_verify(
             message.as_ptr(),
             message.len(),
             signature.as_ptr(),