base-files: fix Linksys upgrade, restore config step

base-files: fix Linksys upgrade, restore config step

It appears that the refactor of the upgrade process for NAND devices                                                                                                                            resulted in the nand_do_upgrade_success step not being called for
devices using the linksys.sh script. As a result, configuration was
not preserved over sysupgrade steps.

This corrects a typo in the call of nand_do_upgrade_failed for ipq40xx
and ipq806x devices using the linksys.sh script.

Fixes: 8634c1080d50 ("ipq40xx: Fix Linksys upgrade, restore config step")
Fixes: 2715aff5df83 ("ipq806x: Fix Linksys upgrade, restore config step")
Signed-off-by: Michael Trinidad <trinidude4@hotmail.com>