sensor: Replace GpioLock with stdplus RAII helper

The old RAII helper was not move safe, although it was never moved in
the current code so it didn't have any effect on runtime safety.

Change-Id: Ica19ed7e60d699d86d0166b356cedb82e4a28b61
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/test/Makefile.am b/test/Makefile.am
index 016409f..a40391a 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -34,10 +34,12 @@
 sensor_unittest_CXXFLAGS = \
 	$(PHOSPHOR_LOGGING_CFLAGS) \
 	$(GPIOPLUS_CFLAGS)
+	$(STDPLUS_CFLAGS)
 sensor_unittest_LDADD = \
 	-lstdc++fs \
 	$(PHOSPHOR_LOGGING_LIBS) \
 	$(GPIOPLUS_LIBS) \
+	$(STDPLUS_LIBS) \
 	$(top_builddir)/sensor.o \
 	$(top_builddir)/hwmon.o \
 	env.o \