misc: pci_endpoint_test: Re-init completion for every test

misc: pci_endpoint_test: Re-init completion for every test

The irq_raised completion used to detect the end of a test case is
initialized when the test device is probed, but never reinitialized again
before a test case. As a result, the irq_raised completion synchronization
is effective only for the first ioctl test case executed. Any subsequent
call to wait_for_completion() by another ioctl() call will immediately
return, potentially too early, leading to false positive failures.

Fix this by reinitializing the irq_raised completion before starting a new
ioctl() test command.

Link: https://lore.kernel.org/r/20230415023542.77601-16-dlemoal@kernel.org
Fixes: 2c156ac71c6b ("misc: Add host side PCI driver for PCI test function device")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Cc: stable@vger.kernel.org