ext4: fix coding style in file.c

Fixed a few coding style issues in file.c

Signed-off-by: Dio Putra <dioput12@gmail.com>
Link: https://lore.kernel.org/r/239fcd8f-d33f-8621-9e82-0416dd3f9c94@gmail.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>