Fix: https://github.com/spacejam/rust-rocksdb/issues/96 (#1)

* Update ffi_util.rs

* Update rocksdb.rs

src/ffi_util.rs

@@ -15,11 +15,10 @@
 
 use libc::{self, c_char, c_void};
 use std::ffi::CStr;
-use std::str;
 
 pub fn error_message(ptr: *const c_char) -> String {
     let cstr = unsafe { CStr::from_ptr(ptr as *const _) };
-    let s = str::from_utf8(cstr.to_bytes()).unwrap().to_owned();
+    let s = String::from_utf8_lossy(cstr.to_bytes()).into();
     unsafe {
         libc::free(ptr as *mut c_void);
     }

src/rocksdb.rs

@@ -911,10 +911,9 @@ fn errors_do_stuff() {
     // The DB will still be open when we try to destroy it and the lock should fail.
     match DB::destroy(&opts, path) {
         Err(s) => {
-            assert!(s ==
-                    Error::new("IO error: lock _rust_rocksdb_error/LOCK: No \
-                                locks available"
-                .to_owned()))
+            let message = s.to_string();
+            assert!(message.find("IO error:").is_some());
+            assert!(message.find("_rust_rocksdb_error/LOCK:").is_some());
         }
         Ok(_) => panic!("should fail"),
     }