[PATCH 4.17 091/101] arm64: ssbd: Skip apply_ssbd if not using dynamic mitigation

4.17-stable review patch. If anyone has any objections, please let me know. -- From: Marc Zyngier commit 986372c4367f46b34a3c0f6918d7fb95cbdf39d6 upstream. In order to avoid checking arm64_ssbd_callback_required on each kernel entry/exit even if no mitigation is required,

[PATCH 4.17 091/101] arm64: ssbd: Skip apply_ssbd if not using dynamic mitigation

4.17-stable review patch. If anyone has any objections, please let me know. -- From: Marc Zyngier commit 986372c4367f46b34a3c0f6918d7fb95cbdf39d6 upstream. In order to avoid checking arm64_ssbd_callback_required on each kernel entry/exit even if no mitigation is required,