fix clippy lint warning

tests/scryer/ffi.rs

@@ -9,7 +9,7 @@ use crate::helper::load_module_test_with_input;
 
 use current_platform::CURRENT_PLATFORM;
 
-const TMP_DIR: &'static str = env!("CARGO_TARGET_TMPDIR");
+const TMP_DIR: &str = env!("CARGO_TARGET_TMPDIR");
 
 // each test is building its own library so that they can easier run in parallel,
 // i.e. don't need to wait for a large dynamic library to compile,