bench: add static qualifier

Signed-off-by: Athan <[email protected]>

Author: kgryte

lib/node_modules/@stdlib/math/base/special/tribonaccif/benchmark/c/benchmark.c

@@ -89,7 +89,7 @@ static float rand_float( void ) {
 * @param n   Tribonacci number to compute
 * @return    Tribonacci number
 */
-int tribonaccif( int n ) {
+static int tribonaccif( int n ) {
 	int a;
 	int b;
 	int c;