Rename *result* to finalize

Implements the API changes from:

RustCrypto/traits#161

The `digest` crate now uses `update` and `finalize` nomenclature
ala the Initialize-Update-Finalize (IUF) interface naming scheme.

Author: tarcieri

examples/md4sum.rs

@@ -28,7 +28,7 @@ fn process<D: Digest + Default, R: Read>(reader: &mut R, name: &str) {
             break;
         }
     }
-    print_result(&sh.result(), name);
+    print_result(&sh.finalize(), name);
 }
 
 fn main() {

src/lib.rs

@@ -14,7 +14,7 @@
 //!
 //! // acquire hash digest in the form of GenericArray,
 //! // which in this case is equivalent to [u8; 16]
-//! let result = hasher.result();
+//! let result = hasher.finalize();
 //! assert_eq!(result[..], hex!("aa010fbc1d14c795d86ef98c95479d17"));
 //! ```
 //!
@@ -140,7 +140,7 @@ impl Default for Md4State {
 }
 
 impl Md4 {
-    fn finalize(&mut self) {
+    fn finalize_inner(&mut self) {
         let state = &mut self.state;
         let l = (self.length_bytes << 3) as u64;
         self.buffer
@@ -167,8 +167,8 @@ impl Update for Md4 {
 impl FixedOutput for Md4 {
     type OutputSize = U16;
 
-    fn fixed_result(mut self) -> GenericArray<u8, Self::OutputSize> {
-        self.finalize();
+    fn finalize_fixed(mut self) -> GenericArray<u8, Self::OutputSize> {
+        self.finalize_inner();
 
         let mut out = GenericArray::default();
         LE::write_u32(&mut out[0..4], self.state.s.0);