ext4: drop read-only check from ext4_force_commit()

JBD2 code will quickly return without doing anything when there's
nothing to commit so there's no point in the read-only check in
ext4_force_commit(). Just drop it.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230616165109.21695-10-jack@suse.cz


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