meetup_rss(write): Remove `mut` from the `stdout` handle

I had copied this from an example in the docs, but the compiler tells me
the `mut` isn't needed. Cool.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/meetup_rss.rs b/src/meetup_rss.rs
index ed58be8..b995571 100644
--- a/src/meetup_rss.rs
+++ b/src/meetup_rss.rs
@@ -26,7 +26,7 @@ pub fn generate(events: &Vec<Event>) -> Result<Channel, String> {
 /// Writes the channel to standard output.
 pub fn write(channel: Channel) {
     let stdout = io::stdout();
-    let mut handle = stdout.lock();
+    let handle = stdout.lock();
 
     channel.write_to(handle);
 }