PCI: xilinx: Fix INTx IRQ domain leak in error paths

PCI: xilinx: Fix INTx IRQ domain leak in error paths

In xilinx_pcie_init_irq_domain(), if xilinx_allocate_msi_domains() fails
after pcie->leg_domain has been successfully created via
irq_domain_create_linear(), the function returns directly without cleaning
up the allocated IRQ domain, resulting in a resource leak. In
xilinx_free_msi_domains(), pcie->leg_domain is also neglected.

Add irq_domain_remove() call in the error path to properly release the
IRQ domain before returning the error. Also rename
xilinx_free_msi_domains() to xilinx_free_irq_domains() and add the release
of pcie->leg_domain to it.

Fixes: 313b64c3ae52 ("PCI: xilinx: Convert to MSI domains")
Suggested-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20251219021615.965-1-vulab@iscas.ac.cn