haiku: Fixed unlocking clipboard twice.

src/video/haiku/SDL_bclipboard.cc

@@ -61,8 +61,6 @@ char *BE_GetClipboardText(_THIS) {
 			/* Presumably the string of characters is ascii-format */
 			clip->FindData("text/plain", B_MIME_TYPE, (const void**)&text,
 				&length);
-		} else {
-			be_clipboard->Unlock();
 		}
 		be_clipboard->Unlock();
 	}