acpi_tables: sdt: Implement Std::is_empty()

This allows the removal of [allow(clippy::len_without_is_empty)]

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

acpi_tables/src/sdt.rs

@@ -38,7 +38,6 @@ pub struct Sdt {
     data: Vec<u8>,
 }
 
-#[allow(clippy::len_without_is_empty)]
 impl Sdt {
     pub fn new(
         signature: [u8; 4],
@@ -124,6 +123,10 @@ impl Sdt {
     pub fn len(&self) -> usize {
         self.data.len()
     }
+
+    pub fn is_empty(&self) -> bool {
+        self.data.is_empty()
+    }
 }
 
 #[cfg(test)]