Set unused variables
Set unused variables

This patch set the GCC attribute unused to variables that are not
used outside the preprocessor guards in src/bitv.c.
This clears all ppc64le warnings.

Signed-off-by: Raphael Moreira Zinsly <797e67f76f4e5e9bfa89a1ff73ccb4f47703a61d@linux.vnet.ibm.com>

frediz/sphde,RajalakshmiS/sphde,frediz/sphde,RajalakshmiS/sphde,sphde/sphde,frediz/sphde,sphde/sphde,RajalakshmiS/sphde,sphde/sphde