Wrap runtime_print! macro in its own scope (#4867)

* Wrap runtime_print! macro in its own scope

Before this fix runtime_print! can be used only once in a scope
because of the name pollution.

* Bump runtime impl versioin (no logic change)

substrate/bin/node/runtime/src/lib.rs

@@ -80,7 +80,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	// implementation changes and behavior does not, then leave spec_version as
 	// is and increment impl_version.
 	spec_version: 214,
-	impl_version: 2,
+	impl_version: 3,
 	apis: RUNTIME_API_VERSIONS,
 };