arm64: armv8_deprecated: update the comments of armv8_deprecated_init()

In commit c0d8832e78 ("arm64: Ensure the instruction emulation is
ready for userspace"), armv8_deprecated_init() was promoted to
core_initcall() but the comments were left unchanged, update it now.

Spotted by some random reading of the code.

Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
[will: "can guarantee" => "guarantees"]
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/kernel/armv8_deprecated.c

@@ -618,7 +618,8 @@ static struct insn_emulation_ops setend_ops = {
 };
 
 /*
- * Invoked as late_initcall, since not needed before init spawned.
+ * Invoked as core_initcall, which guarantees that the instruction
+ * emulation is ready for userspace.
  */
 static int __init armv8_deprecated_init(void)
 {