Update code for Rust 1.82.0

Fixed instance of clippy::single-match.

Test: m out/soong/.intermediates/system/security/keystore2/libkeystore2/android_x86_silvermont_rlib_dylib-std/libkeystore2.rlib.clippy
Bug: 369422063
Change-Id: I0c42e290ff4cb087dd31a61a1b9c153d3c661320
diff --git a/keystore2/src/operation.rs b/keystore2/src/operation.rs
index 9ae8ccf..c11c1f4 100644
--- a/keystore2/src/operation.rs
+++ b/keystore2/src/operation.rs
@@ -308,9 +308,8 @@
         locked_outcome: &mut Outcome,
         err: Result<T, Error>,
     ) -> Result<T, Error> {
-        match &err {
-            Err(e) => *locked_outcome = Outcome::ErrorCode(error_to_serialized_error(e)),
-            Ok(_) => (),
+        if let Err(e) = &err {
+            *locked_outcome = Outcome::ErrorCode(error_to_serialized_error(e))
         }
         err
     }