Drop the deprecated and now removed barrier XFS mount options

Both barrier and nobarrier were deprecated with the 4.10 kernel [1] and
then removed [2] with the 4.19 kernel as now used by Fedora >= 28. Both
should be safe to drop at this point.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4cf4573
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1c02d50

Change-Id: I6871a7765e3e04122d8d546f43d36bb8415383fc

Author: lyarwood

functions

@@ -739,7 +739,7 @@ function create_disk {
 
     # Mount the disk with mount options to make it as efficient as possible
     if ! egrep -q ${storage_data_dir} /proc/mounts; then
-        sudo mount -t xfs -o loop,noatime,nodiratime,nobarrier,logbufs=8  \
+        sudo mount -t xfs -o loop,noatime,nodiratime,logbufs=8  \
             ${disk_image} ${storage_data_dir}
     fi
 }

lib/swift

@@ -607,7 +607,7 @@ function create_swift_disk {
     # Mount the disk with mount options to make it as efficient as possible
     mkdir -p ${SWIFT_DATA_DIR}/drives/sdb1
     if ! egrep -q ${SWIFT_DATA_DIR}/drives/sdb1 /proc/mounts; then
-        sudo mount -t xfs -o loop,noatime,nodiratime,nobarrier,logbufs=8  \
+        sudo mount -t xfs -o loop,noatime,nodiratime,logbufs=8  \
             ${SWIFT_DISK_IMAGE} ${SWIFT_DATA_DIR}/drives/sdb1
     fi