xfs: delete extra space and tab in blank line

delete extra space and tab in blank line, there is no functional change.

Reported-by: Hacash Robot <hacashRobot@santino.com>
Signed-off-by: Xie Shaowen <studentxswpy@163.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>