generic: overlay: disable OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW

The Kconfig symbol help text prompts:
  Disable this to get a possibly more secure configuration, but that
  might not be backward compatible with previous kernels.
  If backward compatibility is not an issue, then it is safe and
  recommended to say N here.

For OpenWrt, when updating firmware, we always update the kernel and
recreate the overlay partition. Therefore, compatibility is not a
problem.

Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
Link: openwrt/openwrt#23126
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

Author: DragonBluep

target/linux/generic/config-6.12

@@ -4552,7 +4552,7 @@ CONFIG_OVERLAY_FS=y
 # CONFIG_OVERLAY_FS_DEBUG is not set
 # CONFIG_OVERLAY_FS_INDEX is not set
 # CONFIG_OVERLAY_FS_METACOPY is not set
-CONFIG_OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW=y
+# CONFIG_OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW is not set
 # CONFIG_OVERLAY_FS_REDIRECT_DIR is not set
 CONFIG_OVERLAY_FS_XINO_AUTO=y
 # CONFIG_P54_COMMON is not set

target/linux/generic/config-6.18

@@ -4709,7 +4709,7 @@ CONFIG_OVERLAY_FS=y
 # CONFIG_OVERLAY_FS_DEBUG is not set
 # CONFIG_OVERLAY_FS_INDEX is not set
 # CONFIG_OVERLAY_FS_METACOPY is not set
-CONFIG_OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW=y
+# CONFIG_OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW is not set
 # CONFIG_OVERLAY_FS_REDIRECT_DIR is not set
 CONFIG_OVERLAY_FS_XINO_AUTO=y
 # CONFIG_OVMF_DEBUG_LOG is not set