nvram: Compile warning cleanups
nvram: Compile warning cleanups

Correct compile warning by removing the unused variable memctrl_data.

Signed-off-by: Nathan Fontenot <4b7bfe500077bf77c5456931a34b0b70e36e0bc6@linux.vnet.ibm.com>

shenki/powerpc-utils,shenki/powerpc-utils,shenki/powerpc-utils