chore(parse): lint fixes

src/rust/src/parser.rs

@@ -426,7 +426,7 @@ impl CcxOptions {
             }
         }
 
-        self.num_input_files = self.num_input_files + 1;
+        self.num_input_files += 1;
 
         0
     }

src/rust/src/utils.rs

@@ -20,6 +20,8 @@ pub unsafe fn string_to_c_char(a: &str) -> *mut ::std::os::raw::c_char {
     s.into_raw()
 }
 
+/// # Safety
+/// The pointer returned has to be deallocated using from_raw() at some point
 pub unsafe fn string_null() -> *mut c_char {
     std::ptr::null_mut()
 }