PCI: Tidy comments

Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions.  No functional change
intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/slot.c

@@ -1,6 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * drivers/pci/slot.c
  * Copyright (C) 2006 Matthew Wilcox <matthew@wil.cx>
  * Copyright (C) 2006-2009 Hewlett-Packard Development Company, L.P.
  *	Alex Chiang <achiang@hp.com>