crypto: qat - fix state restore for banks with exceptions

crypto: qat - fix state restore for banks with exceptions

Change the logic in the restore function to properly handle bank
exceptions.

The check for exceptions in the saved state should be performed before
conducting any other ringstat register checks.
If a bank was saved with an exception, the ringstat will have the
appropriate rp_halt/rp_exception bits set, causing the driver to exit
the restore process with an error. Instead, the restore routine should
first check the ringexpstat register, and if any exception was raised,
it should stop further checks and return without any error. In other
words, if a ring pair is in an exception state at the source, it should
be restored the same way at the destination but without raising an error.

Even though this approach might lead to losing the exception state
during migration, the driver will log the exception from the saved state
during the restore process.

Signed-off-by: Svyatoslav Pankratov <svyatoslav.pankratov@intel.com>
Fixes: bbfdde7d195f ("crypto: qat - add bank save and restore flows")
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>