fix: impl From<Infallible> for Errno

Author: mkroening

src/errno.rs

@@ -1,5 +1,7 @@
 //! System error numbers.
 
+use core::convert::Infallible;
+
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 use thiserror::Error;
 
@@ -669,6 +671,12 @@ pub enum Errno {
 	Hwpoison = 133,
 }
 
+impl From<Infallible> for Errno {
+	fn from(value: Infallible) -> Self {
+		match value {}
+	}
+}
+
 /// Returns the pointer to `errno`.
 #[cfg(all(
 	not(any(feature = "common-os", feature = "nostd")),