Style: Remove unnecessary semicolons from core

Semicolons are not necessary after function definitions or control flow
blocks, and having some code use them makes things inconsistent (and
occasionally can mess up `clang-format`'s formatting).

Removing them is tedious work though, I had to do this manually (regex
+ manual review) as I couldn't find a tool for that. All other code
folders would need to get the same treatment.

core/io/ip.cpp

@@ -54,7 +54,7 @@ struct _IP_ResolverPrivate {
 
 		QueueItem() {
 			clear();
-		};
+		}
 	};
 
 	QueueItem queue[IP::RESOLVER_MAX_QUERIES];