Make fuzzing library just a cdylib/staticlib

There's no reason for it to be an rlib.

Author: TheBlueMatt

fuzz/Cargo.toml

@@ -46,4 +46,4 @@ opt-level = 1
 [lib]
 name = "lightning_fuzz"
 path = "src/lib.rs"
-crate-type = ["rlib", "dylib", "staticlib"]
+crate-type = ["cdylib", "staticlib"]