Remove usage of try! macro, use ? instead (#3097)

We converted the major part of the code a while ago, but some occurences were left. It's a compiler warning on nightly already.

core/src/macros.rs

@@ -66,30 +66,30 @@ macro_rules! tee {
 /// Eliminate some of the boilerplate of deserialization (package ser) by
 /// passing just the list of reader function (with optional single param)
 /// Example before:
-///   let foo = try!(reader.read_u64());
-///   let bar = try!(reader.read_u32());
-///   let fixed_byte_var = try!(reader.read_fixed_bytes(64));
+///   let foo = reader.read_u64()?;
+///   let bar = reader.read_u32()?;
+///   let fixed_byte_var = reader.read_fixed_bytes(64)?;
 /// Example after:
 /// let (foo, bar, fixed_byte_var) = ser_multiread!(reader, read_u64,
 /// read_u32,   read_fixed_bytes(64));
 #[macro_export]
 macro_rules! ser_multiread {
   ($rdr:ident, $($read_call:ident $(($val:expr)),*),*) => {
-    ( $(r#try!($rdr.$read_call($($val),*))),* )
+    ( $($rdr.$read_call($($val),*)?),* )
   }
 }
 
 /// Eliminate some of the boilerplate of serialization (package ser) by
 /// passing directly pairs of writer function and data to write.
 /// Example before:
-///   try!(reader.write_u64(42));
-///   try!(reader.write_u32(100));
+///   reader.write_u64(42)?;
+///   reader.write_u32(100)?;
 /// Example after:
 ///   ser_multiwrite!(writer, [write_u64, 42], [write_u32, 100]);
 #[macro_export]
 macro_rules! ser_multiwrite {
   ($wrtr:ident, $([ $write_call:ident, $val:expr ]),* ) => {
-    $( r#try!($wrtr.$write_call($val)) );*
+    $($wrtr.$write_call($val)? );*
   }
 }