fix: Downgrade #![deny(...)] to #![warn(...)]

In our CI, we explicitly check that no warnings are present (by meanings
of -Dwarnings during build tests). This means that there is no need to
have #![deny(...)] instead of #![warn(...)] directives in the source
code. On the other hand, having deny directives makes prototyping more
annoying, as scrappy code will not compile until all compiler warnings
are fixed (which might not neccessarily make sense when prototyping).

See also #4106

Signed-off-by: Patrick Roy <[email protected]>

src/api_server/src/lib.rs

@@ -1,7 +1,7 @@
 // Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-#![deny(missing_docs)]
+#![warn(missing_docs)]
 
 //! Implements the interface for intercepting API requests, forwarding them to the VMM
 //! and responding to the user.

src/seccompiler/src/lib.rs

@@ -1,7 +1,7 @@
 // Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-#![deny(missing_docs)]
+#![warn(missing_docs)]
 
 //! The library crate that defines common helper functions that are generally used in
 //! conjunction with seccompiler-bin.

src/snapshot/src/lib.rs

@@ -1,7 +1,7 @@
 // Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-#![deny(missing_docs)]
+#![warn(missing_docs)]
 
 //! Provides version tolerant serialization and deserialization facilities and
 //! implements a persistent storage format for Firecracker state snapshots.

src/utils/src/net/mod.rs

@@ -5,7 +5,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the THIRD-PARTY file.
 
-#![deny(missing_docs)]
+#![warn(missing_docs)]
 //! # Network-related utilities
 //!
 //! Provides tools for representing and handling network related concepts like MAC addresses and

src/vmm/src/dumbo/mod.rs

@@ -1,7 +1,7 @@
 // Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-#![deny(missing_docs)]
+#![warn(missing_docs)]
 
 //! Provides helper logic for parsing and writing protocol data units, and minimalist
 //! implementations of a TCP listener, a TCP connection, and an HTTP/1.1 server.

src/vmm/src/io_uring/mod.rs

@@ -1,7 +1,7 @@
 // Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-#![deny(missing_docs)]
+#![warn(missing_docs)]
 
 #[allow(clippy::undocumented_unsafe_blocks)]
 mod bindings;

src/vmm/src/lib.rs

@@ -8,7 +8,7 @@
 //! Virtual Machine Monitor that leverages the Linux Kernel-based Virtual Machine (KVM),
 //! and other virtualization features to run a single lightweight micro-virtual
 //! machine (microVM).
-#![deny(missing_docs)]
+#![warn(missing_docs)]
 #![warn(clippy::undocumented_unsafe_blocks)]
 #![allow(clippy::blanket_clippy_restriction_lints)]
 

src/vmm/src/logger/mod.rs

@@ -1,7 +1,7 @@
 // Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-#![deny(missing_docs)]
+#![warn(missing_docs)]
 
 //! Crate that implements Firecracker specific functionality as far as logging and metrics
 //! collecting.

src/vmm/src/rate_limiter/mod.rs

@@ -1,7 +1,7 @@
 // Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-#![deny(missing_docs)]
+#![warn(missing_docs)]
 
 use std::os::unix::io::{AsRawFd, RawFd};
 use std::time::{Duration, Instant};