tests/integration: Fix tests on debian testing

When we run this:

	mount --bind -o remount,diratime,strictatime "$DIR"

It fails in debian testing, when it is the second time we call this
function in the same bats test (i.e. when $DIR is defined already).

strace shows this syscall failing:

	mount_setattr(3, "", AT_EMPTY_PATH, {attr_set=MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV|MOUNT_ATTR_NOEXEC|MOUNT_ATTR_NOATIME|MOUNT_ATTR_STRICTATIME, attr_clr=MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOATIME|MOUNT_ATTR_STRICTATIME|MOUNT_ATTR_NODIRATIME|0x40, propagation=0 /* MS_??? */, userns_fd=0}, 32) = -1 EINVAL (Invalid argument)

Note it has `MOUNT_ATTR_NOATIME` and `MOUNT_ATTR_STRICTATIME` which
probably causes it to return EINVAL.

This patch simply adds atime to the options, so the mount command now
works and fixes most of the tests in debian testing.

Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.com>

tests/integration/mounts_sshfs.bats

@@ -43,7 +43,7 @@ function setup_sshfs() {
 	fi
 	# Reset atime flags. "diratime" is quite a strange flag, so we need to make
 	# sure it's cleared before we apply the requested flags.
-	mount --bind -o remount,diratime,strictatime "$DIR"
+	mount --bind -o remount,diratime,atime,strictatime "$DIR"
 	# We need to set the mount flags separately on the mount because some mount
 	# flags (such as "ro") are set on the superblock if you do them in the
 	# initial mount, which means that they cannot be cleared by bind-mounts.