NetworkPkg: Update code to be more C11 compliant by using __func__

__FUNCTION__ is a pre-standard extension that gcc and Visual C++ among
others support, while __func__ was standardized in C99.

Since it's more standard, replace __FUNCTION__ with __func__ throughout
NetworkPkg.

Signed-off-by: Rebecca Cran <rebecca@bsdio.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>

NetworkPkg/IScsiDxe/IScsiMisc.c

@@ -875,7 +875,7 @@ IScsiCreateAttempts (
         DEBUG_ERROR,
         "%a: Failed to set 'InitialAttemptOrder' with Guid (%g): "
         "%r\n",
-        __FUNCTION__,
+        __func__,
         &gIScsiConfigGuid,
         Status
         ));
@@ -926,7 +926,7 @@ IScsiCreateAttempts (
         DEBUG_ERROR,
         "%a: Failed to set variable (mPrivate->PortString) with Guid (%g): "
         "%r\n",
-        __FUNCTION__,
+        __func__,
         &gEfiIScsiInitiatorNameProtocolGuid,
         Status
         ));