edition: Eliminate ref keyword

As described in:
https://doc.rust-lang.org/edition-guide/rust-2018/ownership-and-lifetimes/default-match-bindings.html
which also covers the new mental model that the Rust Book will use for
teaching binding modes and has been found to be more friendly for both
beginners and experienced users.

Before:

    match *opt {
        Some(ref v) => ...,
        None => ...,
    }

After:

    match opt {
        Some(v) => ...,
        None => ...,
    }

TEST=cargo check --all-features
TEST=local kokoro

Change-Id: I3c5800a9be36aaf5d3290ae3bd3116f699cb00b7
Reviewed-on: https://chromium-review.googlesource.com/1566669
Commit-Ready: David Tolnay <dtolnay@chromium.org>
Tested-by: David Tolnay <dtolnay@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/net_util/src/lib.rs b/net_util/src/lib.rs
index 591fa99..4122b05 100644
--- a/net_util/src/lib.rs
+++ b/net_util/src/lib.rs
@@ -671,7 +671,7 @@ mod tests {
         match res {
             // We won't have permission in test environments; allow that
             Ok(_t) => {}
-            Err(Error::IoctlError(ref e)) if e.errno() == EPERM => {}
+            Err(Error::IoctlError(e)) if e.errno() == EPERM => {}
             Err(e) => panic!("Unexpected Error:\n{}", e),
         }
     }