hw/vfio/pci.c: Use correct type in trace_vfio_msix_early_setup()

hw/vfio/pci.c: Use correct type in trace_vfio_msix_early_setup()

The tracepoint trace_vfio_msix_early_setup() uses "int" for the type
of the table_bar argument, but we use this to print a uint32_t.
Coverity warns that this means that we could end up treating it as a
negative number.

We only use this in printing the value in the tracepoint, so
mishandling it as a negative number would be harmless, but it's
better to use the right type in the tracepoint.  Use uint64_t to
match how we print the table_offset in the vfio_msix_relo()
tracepoint.

Resolves: Coverity CID 1547690
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Cédric Le Goater <clg@redhat.com>