arm64: ssbd: Drop #ifdefs for PR_SPEC_STORE_BYPASS

mainline inclusion
from mainline-v4.20-rc1
commit 2d1b2a91d56b19636b740ea70c8399d1df249f20
category: feature
bugzilla: 20806
CVE: NA

-------------------------------------------------

Now that we're all merged nicely into mainline, there's no need to check
to see if PR_SPEC_STORE_BYPASS is defined.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NXuefeng Wang <wxf.wang@hisilicon.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/kernel/ssbd.c

@@ -12,9 +12,7 @@
 
 /*
  * prctl interface for SSBD
- * FIXME: Drop the below ifdefery once merged in 4.18.
  */
-#ifdef PR_SPEC_STORE_BYPASS
 static int ssbd_prctl_set(struct task_struct *task, unsigned long ctrl)
 {
 	int state = arm64_get_ssbd_state();
@@ -108,4 +106,3 @@ int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which)
 		return -ENODEV;
 	}
 }
-#endif	/* PR_SPEC_STORE_BYPASS */