iommu/amd: Fix pci_segment memleak in alloc_pci_segment()

iommu/amd: Fix pci_segment memleak in alloc_pci_segment()

Fix a memory leak of struct amd_iommu_pci_segment in alloc_pci_segment()
when system memory (or contiguous memory) is insufficient.

Fixes: 04230c119930 ("iommu/amd: Introduce per PCI segment device table")
Fixes: eda797a27795 ("iommu/amd: Introduce per PCI segment rlookup table")
Fixes: 99fc4ac3d297 ("iommu/amd: Introduce per PCI segment alias_table")
Cc: stable@vger.kernel.org
Signed-off-by: Jinhui Guo <guojinhui.liam@bytedance.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>