UBI: improve comment
UBI: improve comment

Explain better the purpose of thie 'move_to_put' stuff.

Signed-off-by: Artem Bityutskiy <19b5733dcea388885746d36043d3568bba5b4df7@nokia.com>

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