mke2fs: Use ext2fs_flush() only once

mke2fs: Use ext2fs_flush() only once

We are doing ext2fs_flush() twice right now at the end of the mke2fs.
First by directly calling ext2fs_flush() which is intended to write
superblock and fs accounting information. And then it is invoked again
when we are calling ext2fs_close(), only this time, because the fs is
not dirty, we are writing out only superblock.

I think it is bad to call it twice because even when writing only super
block it takes some time on bigger file systems and moreover
ext2fs_close() can fail without any reasonable explanation for the user.
Also ext2fs_flush() is printing out progress and it is confusing for the
users.

Fix all this by removing the ext2fs_flush() and leaving it all to
ext2fs_close(). However we need to introduce new variables to store
check interval and max mount count, because fs structure is freed on
ext2fs_close() and we really want to print those information as the last
info for the user.

[ Fixed type mismatch in a printf format statement -tytso]

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>