use * for block comments in multiple lines according to kernel coding
style

Reported by: checkpatch.pl
Signed-off-by: Ashish Kalra <eashishkalra@gmail.com>
Reviewed-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>