staging: exfat: Replace printk with pr_info

pr_info is preferred to use than printk.
pr_info calls printk with KERN_INFO macros by itself.

Signed-off-by: JieunKim <jieun.kim4758@gmail.com>
Link: https://lore.kernel.org/r/20200210091421.12335-1-jieun.kim4758@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>