Don't output "exec() finished with..." error message

It's useless because the result of the compiler is always evident (it outputs
either diagnostics or an exception stack trace)

compiler/cli/src/org/jetbrains/jet/cli/common/CLICompiler.java

@@ -210,11 +210,7 @@ public abstract class CLICompiler<A extends CommonCompilerArguments> {
     @NotNull
     public static ExitCode doMainNoExit(@NotNull CLICompiler compiler, @NotNull String[] args) {
         try {
-            ExitCode rc = compiler.exec(System.err, args);
-            if (rc != OK) {
-                System.err.println("exec() finished with " + rc + " return code");
-            }
-            return rc;
+            return compiler.exec(System.err, args);
         }
         catch (CompileEnvironmentException e) {
             System.err.println(e.getMessage());

compiler/integration-tests/testData/compilationFailed/hello.compile.expected

@@ -1,6 +1,5 @@
 
 ERR:
 ERROR: [TestData]/hello.kt: (4, 5) Unresolved reference: a
-exec() finished with COMPILATION_ERROR return code
 
 Return code: 1

compiler/integration-tests/testData/syntaxErrors/test.compile.expected

@@ -1,6 +1,5 @@
 
 ERR:
 ERROR: [TestData]/test.kt: (4, 20) Expecting an element
-exec() finished with COMPILATION_ERROR return code
 
 Return code: 1