PCI: rockchip-host: Fix "Unexpected Completion" log message

Fix the debug message for the PCIE_CORE_INT_UCR interrupt to clearly
indicate "Unexpected Completion" instead of a duplicate "malformed TLP"
message.

Fixes: e77f847d ("PCI: rockchip: Add Rockchip PCIe controller support")
Signed-off-by: Hans Zhang <18255117159@163.com>
[mani: added fixes tag]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com>
Link: https://patch.msgid.link/20250607160201.807043-2-18255117159@163.com