ircd: Fix comment.

include/ircd/exception.h

@@ -139,14 +139,14 @@ struct name                                                                   \
     }                                                                         \
 };
 
+namespace ircd
+{
 	/// Root error exception type. Inherit from this.
 	/// List your own exception somewhere else (unless you're overhauling libircd).
 	/// example, in your namespace:
 	///
 	/// IRCD_EXCEPTION(ircd::error, error)
 	///
-namespace ircd
-{
 	IRCD_EXCEPTION(exception,  error)            // throw ircd::error("something bad")
 	IRCD_EXCEPTION(error, user_error)            // throw ircd::user_error("something silly")
 }