spapr_pci: convert g_malloc() to g_new()

spapr_pci: convert g_malloc() to g_new()

When allocating an array, it is a recommended coding practice to call
g_new(FooType, n) instead of g_malloc(n * sizeof(FooType)) because
it takes care to avoid overflow when calculating the size of the
allocated block and it returns FooType *, which allows the compiler
to perform type checking.

Signed-off-by: Greg Kurz <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Signed-off-by: David Gibson <[email protected]>