IB/hfi1: constify vm_operations_struct

vm_operations_struct are not supposed to change at runtime.
vm_area_struct structure working with const vm_operations_struct.
So mark the non-const vm_operations_struct structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hfi1/file_ops.c

@@ -120,7 +120,7 @@ static const struct file_operations hfi1_file_ops = {
 	.llseek = noop_llseek,
 };
 
-static struct vm_operations_struct vm_ops = {
+static const struct vm_operations_struct vm_ops = {
 	.fault = vma_fault,
 };