sgi-xpc: Use GFP_ATOMIC for kmalloc in atomic context.

sgi-xpc: Use GFP_ATOMIC for kmalloc in atomic context.

xpc_send_activate_IRQ_uv is called from
 <-xpc_send_activate_IRQ_part_uv
 <-xpc_indicate_partition_disengaged_uv
  (xpc_arch_ops.indicate_partition_disengaged)
 <-xpc_die_deactivate
 <-xpc_system_die

xpc_system_die is registered by atomic_notifier_chain_register,
which indicates xpc_system_die may be called in atomic context.
So the kmalloc in xpc_send_activate_IRQ_uv may be in atomic context.

Use GFP_ATOMIC instead of GFP_KERNEL in kmalloc.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Link: https://lore.kernel.org/r/20190805125625.24963-1-huangfq.daxian@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>