misc/pvpanic-pci: Fix error handling in 'pvpanic_pci_probe()'

There is no error handling path in the probe function.
Switch to managed resource so that errors in the probe are handled easily
and simplify the remove function accordingly.

Fixes: db3a4f0a

 ("misc/pvpanic: add PCI driver")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/ab071b1f4ed6e1174f9199095fb16a58bb406090.1621665058.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>