util: Use standard ether functions for conversion

This should be slightly faster and is more standard for interop with
other programs using the same conversion functions.

Change-Id: I4d7a2cb4df2173afda421c5b41ee5e98e722d6c6
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/test/test_util.cpp b/test/test_util.cpp
index 4e39821..d2be390 100644
--- a/test/test_util.cpp
+++ b/test/test_util.cpp
@@ -177,7 +177,7 @@
     EXPECT_EQ(false, phosphor::network::mac_address::validate(macaddress));
 
     macaddress = "F6:C6:E6:6:B0:D3";
-    EXPECT_EQ(false, phosphor::network::mac_address::validate(macaddress));
+    EXPECT_EQ(true, phosphor::network::mac_address::validate(macaddress));
 
     macaddress = "F6:C6:E6:06:B0:D3";
     EXPECT_EQ(true, phosphor::network::mac_address::validate(macaddress));