clippy: Resolve if_same_then_else

Suppressing the lint locally because by the author's and reviewers'
judgement this was the clearest way to write this code. The lint is
still valuable for catching mistakes in copied and pasted code
elsewhere.

TEST=bin/clippy

Change-Id: I77477fce51571220fd6259072519b31764a15aeb
Reviewed-on: https://chromium-review.googlesource.com/1566737
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>

bin/clippy

@@ -39,7 +39,6 @@ SUPPRESS=(
 
     # To be resolved or suppressed locally.
     cast_ptr_alignment
-    if_same_then_else
     ptr_arg
 
     # We don't care about these lints. Okay to remain suppressed globally.

devices/src/virtio/queue.rs

@@ -111,6 +111,7 @@ impl<'a> DescriptorChain<'a> {
         }
     }
 
+    #[allow(clippy::if_same_then_else)]
     fn is_valid(&self) -> bool {
         if self
             .mem

vhost/src/lib.rs

@@ -165,6 +165,7 @@ pub trait Vhost: AsRawFd + std::marker::Sized {
     }
 
     // TODO(smbarber): This is copypasta. Eliminate the copypasta.
+    #[allow(clippy::if_same_then_else)]
     fn is_valid(
         &self,
         queue_max_size: u16,