build_library: enable xattr on squashfs

Remove flag that disables xattr (extended attributes) on squashfs so that
squashfs will also support file capabilities.

BUG=chromium:223953
TEST='~/trunk/src/build_image --board=samus' still works

Build and boot an image.
1) Build a panther_embedded image
2) Run 'mount_gpt_image.sh --board=panther_embedded --noread_only \
   --from $IMG_PATH'
   where $IMG_PATH is the path to the binary built in step 1. This will
   mount the image as (pseudo-)read-write.
3) Run 'sudo getcap /tmp/m/bin/ping' and verify that no output is
   returned.
4) Run 'sudo setcap cap_net_raw=ep /tmp/m/bin/cp'
5) Run 'sudo getcap /tmp/m/bin/ping' again and verify that /bin/cp now
   has the cap_net_raw=ep file capability set.
6) Run '~/trunk/src/scripts/mount_gpt_image.sh --board=panther_embedded\
   --unmount --delete_mountpts --from $IMG_PATH' to unmount image.
7) Run '~/trunk/src/scripts/mount_gpt_image.sh --board=panther_embedded\
   --read_only --from $IMG_PATH' to mount the image as read-only.
8) Repeat step 5.

Change-Id: I80660b02f61fd569b62cdb3406b098959e95578f
Reviewed-on: https://chromium-review.googlesource.com/267341
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Reviewed-by: Samuel Tan <samueltan@chromium.org>
Commit-Queue: Samuel Tan <samueltan@chromium.org>
Tested-by: Samuel Tan <samueltan@chromium.org>
1 file changed