Revert "make_netboot: Change use flags to right name 'factory_netboot_ramfs'."

Reverting due to build failures of chromeos-initramfs in Archive (now noted in crbug/477744).

BUG=chromium:640343

This reverts commit 91141147466292d86e14a0dda4431bf021d68e56.

Change-Id: I529c5ca926db3c18ac350c33a72c6692ed66c966
Reviewed-on: https://chromium-review.googlesource.com/374484
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
Commit-Queue: Bernie Thompson <bhthompson@chromium.org>
Tested-by: Bernie Thompson <bhthompson@chromium.org>
diff --git a/make_netboot.sh b/make_netboot.sh
index 63f6420..03ea092 100755
--- a/make_netboot.sh
+++ b/make_netboot.sh
@@ -64,7 +64,7 @@
 
 # Build initramfs network boot image
 echo "Building kernel"
-export USE="fbconsole vtconsole factory_netboot_ramfs tpm i2cdev vfat"
+export USE="fbconsole vtconsole netboot_ramfs tpm i2cdev vfat"
 export EMERGE_BOARD_CMD="emerge-${FLAGS_board}"
 emerge_custom_kernel ${temp_build_path}