Fix style issues

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Replace seq_printf with seq_puts if possible

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Shorten stats operations

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Rename internal stats

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>