[lock] Modernize to C++17 nested namespaces

esphome/components/lock/automation.h

@@ -4,8 +4,7 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 
-namespace esphome {
-namespace lock {
+namespace esphome::lock {
 
 template<typename... Ts> class LockAction : public Action<Ts...> {
  public:
@@ -72,5 +71,4 @@ class LockUnlockTrigger : public Trigger<> {
   }
 };
 
-}  // namespace lock
-}  // namespace esphome
+}  // namespace esphome::lock

esphome/components/lock/lock.cpp

@@ -3,8 +3,7 @@
 #include "esphome/core/controller_registry.h"
 #include "esphome/core/log.h"
 
-namespace esphome {
-namespace lock {
+namespace esphome::lock {
 
 static const char *const TAG = "lock";
 
@@ -108,5 +107,4 @@ LockCall &LockCall::set_state(const std::string &state) {
 }
 const optional<LockState> &LockCall::get_state() const { return this->state_; }
 
-}  // namespace lock
-}  // namespace esphome
+}  // namespace esphome::lock

esphome/components/lock/lock.h

@@ -7,8 +7,7 @@
 #include "esphome/core/preferences.h"
 #include <initializer_list>
 
-namespace esphome {
-namespace lock {
+namespace esphome::lock {
 
 class Lock;
 
@@ -177,5 +176,4 @@ class Lock : public EntityBase {
   ESPPreferenceObject rtc_;
 };
 
-}  // namespace lock
-}  // namespace esphome
+}  // namespace esphome::lock