PCI: dwc: Free MSI in dw_pcie_host_init() error path

If we ever did MSI-related initializations, we need to call
dw_pcie_free_msi() in the error code path.

Remove the IS_ENABLED(CONFIG_PCI_MSI) check for MSI init because
pci_msi_enabled() already has a stub for !CONFIG_PCI_MSI.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>