Rust wrapper: make ECC::verify_hash C result check more strict

Fixes F-1989

Author: holtrop-wolfssl

wrapper/rust/wolfssl-wolfcrypt/src/ecc.rs

@@ -1964,7 +1964,7 @@ impl ECC {
         if rc != 0 {
             return Err(rc);
         }
-        Ok(res != 0)
+        Ok(res == 1)
     }
 }