pci: designware: Update MSI mapping unconditionally

pci: designware: Update MSI mapping unconditionally

Expression to calculate update_msi_mapping in code handling writes to
DESIGNWARE_PCIE_MSI_INTR0_ENABLE is missing an ! operator and should
be:

    !!root->msi.intr[0].enable ^ !!val;

so that MSI mapping is updated when enabled transitions from either
"none" -> "any" or "any" -> "none". Since that register shouldn't be
written to very often, change the code to update MSI mapping
unconditionally instead of trying to fix the update_msi_mapping logic.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: qemu-devel@nongnu.org
Cc: qemu-arm@nongnu.org
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>