Remove redundant bssl_sys import

R=agl@chromium.org

Bug: chromium:326247202
Change-Id: I6c1bb77da2ce428fd7c9be3c0ea542ca8c84d443
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/66449
Reviewed-by: danakj <danakj@chromium.org>
Auto-Submit: Zequan Wu <zequanwu@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
diff --git a/rust/bssl-crypto/src/digest.rs b/rust/bssl-crypto/src/digest.rs
index e5578e5..645ab80 100644
--- a/rust/bssl-crypto/src/digest.rs
+++ b/rust/bssl-crypto/src/digest.rs
@@ -32,7 +32,6 @@
 
 use crate::{sealed, FfiSlice, ForeignTypeRef};
 use alloc::vec::Vec;
-use bssl_sys;
 
 #[non_exhaustive]
 #[doc(hidden)]