sandbox/sail: Fixes the use of __restrict__ type qualifier.

The way these type qualifiers were used causing problems with clang. This
commit fixes their usage.

See http://gcc.gnu.org/onlinedocs/gcc/Restricted-Pointers.html

git-svn-id: https://svn.code.sf.net/p/kaldi/code/sandbox/sail@3703 5e6a8d80-dfce-4ca6-a32a-6e07a63d50c8