Fix clippy warnings

src/fs.rs

@@ -719,6 +719,10 @@ impl<'a, 'b, Storage: driver::Storage> File<'a, 'b, Storage> {
         io::result_from(return_code as usize, return_code)
     }
 
+    pub fn is_empty(&self) -> Result<bool> {
+        self.len().map(|l| l == 0)
+    }
+
     /// Truncates or extends the underlying file, updating the size of this file to become size.
     ///
     /// If the size is less than the current file's size, then the file will be shrunk. If it is

src/lib.rs

@@ -1,4 +1,6 @@
 #![cfg_attr(not(test), no_std)]
+// FIXME
+#![allow(clippy::missing_safety_doc)]
 
 /*!
 

src/path.rs

@@ -202,6 +202,12 @@ unsafe fn strlen(mut s: *const c_char) -> size_t {
     n
 }
 
+impl Default for PathBuf {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl PathBuf {
     pub fn new() -> Self {
         Self {