fix memset size for fixed array

fix memset size for fixed array

Use sizeof on fixed array instead of hard-coded value.

The hard-coded value did not account for the size of the
data type (uint32_t) and therefore did not zero out the
entire array, rather it only zero'd out number of elements
bytes.

This prevents compiler memset-elt-size error when using
-Wall -Werror compiler flags.

Signed-off-by: U. Artie Eoff <ullysses.a.eoff@intel.com>