staging/rts_pstor: Use pr_ or dev_ printks in rtsx.c

fixed some checkpatch warnings.
-WARNING: Prefer pr_info(... to printk(KERN_INFO, ...
-WARNING: Prefer pr_err(... to printk(KERN_ERR, ...
-WARNING: quoted string split across lines

And added pr_fmt.
Signed-off-by: Toshiaki Yamane <yamanetoshi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>