Simplify RawSocketWriter

Does not need to use an allocator anymor.
Just uses the internal buffer properly.

src/main.zig

@@ -47,7 +47,7 @@ pub fn main() !void {
     }
 
     var sock_buffer: [2048]u8 = undefined;
-    var rawSocketWriter: RawSocketWriter = try .init("enp7s0", &sock_buffer, gpa); // /proc/net/dev
+    var rawSocketWriter: RawSocketWriter = try .init("enp7s0", &sock_buffer); // /proc/net/dev
     var client = try SaprusClient.init(&rawSocketWriter.interface);
     defer client.deinit();