Fix entity-manager issues against GCC8

move std::experimental::filesystem to std::filesystem, and fix an error
in a function that returns bool, but didn't contain a return statement.

Change-Id: Iaedfc5ea189fa5382e4b29be5854cb72915a742d
Signed-off-by: Ed Tanous <ed.tanous@intel.com>
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/src/FruDevice.cpp b/src/FruDevice.cpp
index 0590717..ca0e541 100644
--- a/src/FruDevice.cpp
+++ b/src/FruDevice.cpp
@@ -37,7 +37,7 @@
 #include <linux/i2c-dev.h>
 }
 
-namespace fs = std::experimental::filesystem;
+namespace fs = std::filesystem;
 static constexpr bool DEBUG = false;
 static size_t UNKNOWN_BUS_OBJECT_COUNT = 0;
 constexpr size_t MAX_FRU_SIZE = 512;
@@ -59,7 +59,7 @@
 
 static bool isMuxBus(size_t bus)
 {
-    return is_symlink(std::experimental::filesystem::path(
+    return is_symlink(std::filesystem::path(
         "/sys/bus/i2c/devices/i2c-" + std::to_string(bus) + "/mux_device"));
 }