When kvasprintf() fails to allocate memory, it returns a NULL pointer.
Return error from pci_request_irq() so we don't dereference it.

[bhelgaas: commit log]
Fixes: 704e8953 ("PCI/irq: Add pci_request_irq() and pci_free_irq() helpers")
Link: https://lore.kernel.org/r/20221121020029.3759444-1-zengheng4@huawei.comSigned-off-by: NZeng Heng <zengheng4@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>