mm/vmalloc: use kmalloc_array() instead of kmalloc()

mm/vmalloc: use kmalloc_array() instead of kmalloc()

The number of NUMA nodes (nr_node_ids) is bounded, so overflow is not a
practical concern here.  However, using kmalloc_array() better reflects
the intent to allocate an array of unsigned ints, and improves consistency
with other NUMA-related allocations.

No functional change intended.

Link: https://lkml.kernel.org/r/20251018201207.27441-1-mehdi.benhadjkhelifa@gmail.com
Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Khalid Aziz <khalid@kernel.org>
Cc: David Hunter <david.hunter.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>