COMP: Remove call for non-existent variable in Nifti debugging.

"tobuffer" is not defined, causing a build error with
 __USE_VERY_VERBOSE_NIFTI_DEBUGGING__.

Suggested-by: Kris Thielemans <kris.f.thielemans@gmail.com>

Change-Id: I053ed70aa767d48a380407dec43d906086248b27
Merge topic 'NiftiDebugging'

ece4fa97 COMP: Remove call for non-existent variable in Nifti debugging.