We are not handling all divide by zero cases in paprd.
Add additional checks for divide by zero cases in papard.

This patch has fixes intended for kernel 2.6.36.

Cc: stable@kernel.org
Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>