vfio/pci: Move to single error path

Enabling and disabling of an interrupt involves several steps
that can fail. Cleanup after failure is done when the error
is encountered, resulting in some repetitive code.

Support for dynamic contexts will introduce more steps during
interrupt enabling and disabling.

Transition to centralized exit path in preparation for dynamic
contexts to eliminate duplicate error handling code.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/72dddae8aa710ce522a74130120733af61cffe4d.1683740667.git.reinette.chatre@intel.com


Signed-off-by: Alex Williamson <alex.williamson@redhat.com>