libcamera: utils: Don't use C++17 nested namespaces

Nesting namespace names in a single namespace declaration is a C++17
feature. As libcamera depends on C++11 only, nest two separate namespace
declarations instead.

Reported-by: Shik Chen <shik@google.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

src/libcamera/include/utils.h

@@ -11,7 +11,9 @@
 
 #define ARRAY_SIZE(a)	(sizeof(a) / sizeof(a[0]))
 
-namespace libcamera::utils {
+namespace libcamera {
+
+namespace utils {
 
 /* C++11 doesn't provide std::make_unique */
 template<typename T, typename... Args>
@@ -20,6 +22,8 @@ std::unique_ptr<T> make_unique(Args&&... args)
 	return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
 }
 
-} /* namespace libcamera::utils */
+} /* namespace utils */
+
+} /* namespace libcamera */
 
 #endif /* __LIBCAMERA_UTILS_H__ */