Refactor ifs into a match

Co-authored-by: Damir Jelić <[email protected]>
Signed-off-by: Andy Balaam <[email protected]>

crates/matrix-sdk-crypto/src/types/events/utd_cause.rs

@@ -217,19 +217,19 @@ impl UtdCause {
      * ```
      */
     fn determine_historical(crypto_context_info: CryptoContextInfo) -> UtdCause {
-        if crypto_context_info.backup_exists_on_server {
-            if crypto_context_info.is_backup_configured
-                || crypto_context_info.this_device_is_verified
-            {
+        let backup_exist = crypto_context_info.backup_exists_on_server;
+        let is_backup_configured = crypto_context_info.is_backup_configured;
+        let are_we_verified = crypto_context_info.this_device_is_verified;
+
+        match (backup_exist, is_backup_configured || are_we_verified) {
+            (true, true) => {
                 // Either backup download is working but we still don't have the key, or backup
                 // download *isn't* working despite being verified. In either
                 // case, we shrug and give an `Unknown` cause.
                 UtdCause::Unknown
-            } else {
-                UtdCause::HistoricalMessageAndDeviceIsUnverified
             }
-        } else {
-            UtdCause::HistoricalMessageAndBackupIsDisabled
+            (true, false) => UtdCause::HistoricalMessageAndDeviceIsUnverified,
+            (false, _) => UtdCause::HistoricalMessageAndBackupIsDisabled,
         }
     }
 }