mfd: ab8500-debug: Convert to kstrtoul_from_user
mfd: ab8500-debug: Convert to kstrtoul_from_user

Use kstrtoul_from_user for getting an unsigned long from userspace
which is less error prone.

Signed-off-by: srinidhi kasagar <36bfbb1c304809ea0032a12663697185f6a407dd@stericsson.com>
Signed-off-by: Linus Walleij <9cd9d802d23c0ed5e224beabf4ae4a5c478746ef@stericsson.com>
Signed-off-by: Lee Jones <630e34333487a351a857f6b705e04d30b37c1629@linaro.org>
Reviewed-by: Jonas ABERG <39fc1ce28f1cdf552b189618c2eb1c1bd8a697e7@stericsson.com>
Acked-by: Samuel Ortiz <0ba86cb3f08bbb861958e54bd3438887adb4263c@linux.intel.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas