Fix some warnings by cppcheck

Warning message:
sysfs.hpp:27:5: style: Class 'SysfsLed' has a constructor with 1 argument that is not explicit. [noExplicitConstructor]
    SysfsLed(std::filesystem::path&& root) : root(std::move(root))
    ^
test/sysfs.cpp:53:5: style: Class 'FakeSysfsLed' has a constructor with 1 argument that is not explicit. [noExplicitConstructor]
    FakeSysfsLed(fs::path&& path) : SysfsLed(std::move(path))

Tested: Use cppcheck to build successfully and eliminate the above
warning message.

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Ib6cef5cb4eb6f44f3b8dcc0e9d2b95bd15c9818a
diff --git a/sysfs.hpp b/sysfs.hpp
index fbf5e78..752bc57 100644
--- a/sysfs.hpp
+++ b/sysfs.hpp
@@ -24,7 +24,7 @@
 class SysfsLed
 {
   public:
-    SysfsLed(std::filesystem::path&& root) : root(std::move(root))
+    explicit SysfsLed(std::filesystem::path&& root) : root(std::move(root))
     {}
     SysfsLed() = delete;
     SysfsLed(const SysfsLed& other) = delete;
diff --git a/test/sysfs.cpp b/test/sysfs.cpp
index 7a65b94..7a23ed5 100644
--- a/test/sysfs.cpp
+++ b/test/sysfs.cpp
@@ -50,7 +50,7 @@
     }
 
   private:
-    FakeSysfsLed(fs::path&& path) : SysfsLed(std::move(path))
+    explicit FakeSysfsLed(fs::path&& path) : SysfsLed(std::move(path))
     {
         std::string attrs[4] = {BRIGHTNESS, TRIGGER, DELAY_ON, DELAY_OFF};
         for (const auto& attr : attrs)