cpplint: Ignore incomplete declaration of namespaces

Within some of the internal headers, we do not have a complete declaration of
some namespaces, and that's ok. Most of these cases are within macros anyway.

Since there's no sane way to make cpplint happy otherwise, lets ignore these
warnings instead.

Signed-off-by: Gergely Nagy <algernon@keyboard.io>

src/kaleidoscope_internal/LEDModeManager.h

@@ -405,9 +405,9 @@ class LEDModeManager {
    LEDModeManager::setupLEDMode(&::PLUGIN);
 
 #define _INIT_LED_MODE_MANAGER(...)                                            \
-   namespace kaleidoscope {                                             __NL__ \
-   namespace internal {                                                 __NL__ \
-   namespace led_mode_management {                                      __NL__ \
+   namespace kaleidoscope { /* NOLINT(build/namespaces) */              __NL__ \
+   namespace internal { /* NOLINT(build/namespaces) */                  __NL__ \
+   namespace led_mode_management { /* NOLINT(build/namespaces) */       __NL__ \
                                                                         __NL__ \
       /* Setup the array-like data structure that stores                __NL__ \
        * LEDModeFactories */                                            __NL__ \

src/kaleidoscope_internal/sketch_exploration/keymap_exploration.h

@@ -18,8 +18,8 @@
 
 #include "kaleidoscope/key_defs.h"
 
-namespace kaleidoscope {
-namespace sketch_exploration {
+namespace kaleidoscope { // NOLINT(build/namespaces)
+namespace sketch_exploration { // NOLINT(build/namespaces)
 
 // A simple keymap adaptor class that makes the keymap conveniently accessible.
 // at compiletime.
@@ -214,7 +214,7 @@ extern void pluginsExploreSketch();
 // exploreSketch<_Sketch>(...)-hook.
 //
 #define _INIT_KEYMAP_EXPLORATION                                               \
-  namespace kaleidoscope {                                                     \
+  namespace kaleidoscope { /* NOLINT(build/namespaces) */                      \
   namespace sketch_exploration {                                               \
                                                                                \
      template<bool _keymap_is_empty>                                           \