mfd: Use NULL to initialise NULL pointers in ab8500-debugfs
mfd: Use NULL to initialise NULL pointers in ab8500-debugfs

Partly for coding style reasons, but mostly because sparse warns on it.

Signed-off-by: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@opensource.wolfsonmicro.com>
Acked-by: Mattias Wallin <bcfca4ab290675f2d1e16d1b4ebb2a9917cb944a@stericsson.com>
Signed-off-by: Samuel Ortiz <0ba86cb3f08bbb861958e54bd3438887adb4263c@linux.intel.com>

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