PCI/ERR: Combine pci_channel_io_frozen cases

pcie_do_recovery() had two "if (state == pci_channel_io_frozen)" cases
right after each other.  Combine them to make this easier to read.  No
functional change intended.

Link: https://lore.kernel.org/r/20200317170654.GA23125@infradead.org
[bhelgaas: split from https://lore.kernel.org/r/a255fcb3a3fdebcd90f84e08b555f1786eb8eba2.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com

]
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>