misc: code cleanup

Author: DennisDyallo

Yubico.YubiKey/src/Yubico/YubiKey/Piv/Commands/GetMetadataCommand.cs

@@ -140,7 +140,7 @@ public GetMetadataCommand(byte slotNumber)
         /// </remarks>
         public GetMetadataCommand()
         {
-            _slotNumber = 0;
+            
         }
 
         /// <inheritdoc />

Yubico.YubiKey/src/Yubico/YubiKey/Piv/PivSession.Crypto.cs

@@ -434,20 +434,11 @@ private byte[] PerformPrivateKeyOperation(
             var metadata = GetMetadataInternal(slotNumber);
             if (metadata is not null)
             {
-                // We know the algorithm based on the input data. Is it the
-                // algorithm of the key in the slot?
-                // We can make this check with metadata. Without metadata there's
-                // no way to know until we try to perform the operation.
                 if (metadata.Algorithm != algorithm)
                 {
                     throw new ArgumentException(algorithmExceptionMessage);
                 }
-
-                // If the metadata says Never, then pinRequired is false.
-                // If the metadata says Once, and the PIN is verified, then the
-                // PIN is not required.
-                // The only other case is Always which means we set the
-                // pinRequired to true, but we init that variable to true.
+                
                 if (metadata.PinPolicy == PivPinPolicy.Never ||
                     (metadata.PinPolicy == PivPinPolicy.Once && PinVerified))
                 {

Yubico.YubiKey/src/Yubico/YubiKey/Piv/PivSession.Pin.cs

@@ -293,8 +293,8 @@ public bool TryVerifyPin(ReadOnlyMemory<byte> pin, out int? retriesRemaining)
                 return true;
             }
 
-            retriesRemaining = response.GetData();
-            if ((retriesRemaining ?? 1) == 0)
+            retriesRemaining = response.GetData() ?? 1;
+            if (retriesRemaining == 0)
             {
                 throw new SecurityException(
                     string.Format(