misc: pci_endpoint_test: Avoid issue of interrupts remaining after request_irq error

In the Linux kernel, the following vulnerability has been resolved:

misc: pci_endpoint_test: Avoid issue of interrupts remaining after request_irq error

After devm_request_irq() fails with error in pci_endpoint_test_request_irq(),

the pci_endpoint_test_free_irq_vectors() is called assuming that all IRQs

have been released.

However, some requested IRQs remain unreleased, so there are still

/proc/irq/* entries remaining, and this results in WARN() with the

following message:

remove_proc_entry: removing non-empty directory 'irq/30', leaking at least 'pci-endpoint-test.0'

WARNING: CPU: 0 PID: 202 at fs/proc/generic.c:719 remove_proc_entry +0x190/0x19c

To solve this issue, set the number of remaining IRQs to test->num_irqs,

and release IRQs in advance by calling pci_endpoint_test_release_irq().

[kwilczynski: commit log]