libcamera: utils: Identify the 'real' build path

Call realpath() to strip out any levels of indirection required in
referencing the root build directory.

This simplifies the debug output when reporting and parsing paths.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/utils.cpp

@@ -386,7 +386,16 @@ std::string libcameraBuildPath()
 	if (ret == 0)
 		return std::string();
 
-	return dirname(info.dli_fname) + "/../../";
+	std::string path = dirname(info.dli_fname) + "/../../";
+
+	char *real = realpath(path.c_str(), nullptr);
+	if (!real)
+		return std::string();
+
+	path = real;
+	free(real);
+
+	return path + "/";
 }
 
 /**