Fix tracing failed calls.

ethcore/evm/src/interpreter/informant.rs

@@ -39,12 +39,12 @@ mod inner {
 	use std::collections::HashMap;
 	use std::time::{Instant, Duration};
 
-	use evm::interpreter::stack::Stack;
-	use evm::instructions::{Instruction, InstructionInfo, INSTRUCTIONS};
-	use evm::{CostType};
-
 	use bigint::prelude::U256;
 
+	use interpreter::stack::Stack;
+	use instructions::{Instruction, InstructionInfo, INSTRUCTIONS};
+	use CostType;
+
 	macro_rules! evm_debug {
 		($x: expr) => {
 			$x
@@ -110,7 +110,7 @@ mod inner {
 		}
 
 		pub fn after_instruction(&mut self, instruction: Instruction) {
-			let mut stats = self.stats.entry(instruction).or_insert_with(|| Stats::default());
+			let stats = self.stats.entry(instruction).or_insert_with(|| Stats::default());
 			let took = self.last_instruction.elapsed();
 			stats.note(took);
 		}

ethcore/evm/src/lib.rs

@@ -28,6 +28,7 @@ extern crate memory_cache;
 #[macro_use]
 extern crate lazy_static;
 
+#[macro_use]
 extern crate log;
 
 #[cfg(feature = "jit")]