bench: fix random value generation

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
  - task: lint_filenames
    status: passed
  - task: lint_editorconfig
    status: passed
  - task: lint_markdown
    status: na
  - task: lint_package_json
    status: na
  - task: lint_repl_help
    status: na
  - task: lint_javascript_src
    status: na
  - task: lint_javascript_cli
    status: na
  - task: lint_javascript_examples
    status: na
  - task: lint_javascript_tests
    status: na
  - task: lint_javascript_benchmarks
    status: na
  - task: lint_python
    status: na
  - task: lint_r
    status: na
  - task: lint_c_src
    status: na
  - task: lint_c_examples
    status: na
  - task: lint_c_benchmarks
    status: passed
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
    status: na
  - task: lint_typescript_declarations
    status: na
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

Author: kgryte

lib/node_modules/@stdlib/blas/base/sgemv/benchmark/c/benchmark.length.c

@@ -103,11 +103,12 @@ static double benchmark1( int iterations, int N ) {
 	int i;
 	int j;
 
-	for ( i = 0, j = 0; i < N; i++, j += 2 ) {
+	for ( i = 0; i < N; i++ ) {
 		x[ i ] = ( rand_float()*20.0f ) - 10.0f;
 		y[ i ] = ( rand_float()*20.0f ) - 10.0f;
-		A[ j ] = ( rand_float()*20.0f ) - 10.0f;
-		A[ j+1 ] = ( rand_float()*20.0f ) - 10.0f;
+		for ( j = 0; j < N; j++ ) {
+			A[ (i*N)+j ] = ( rand_float()*20.0f ) - 10.0f;
+		}
 	}
 	t = tic();
 	for ( i = 0; i < iterations; i++ ) {
@@ -141,11 +142,12 @@ static double benchmark2( int iterations, int N ) {
 	int i;
 	int j;
 
-	for ( i = 0, j = 0; i < N; i++, j += 2 ) {
+	for ( i = 0; i < N; i++ ) {
 		x[ i ] = ( rand_float()*20.0f ) - 10.0f;
 		y[ i ] = ( rand_float()*20.0f ) - 10.0f;
-		A[ j ] = ( rand_float()*20.0f ) - 10.0f;
-		A[ j+1 ] = ( rand_float()*20.0f ) - 10.0f;
+		for ( j = 0; j < N; j++ ) {
+			A[ (i*N)+j ] = ( rand_float()*20.0f ) - 10.0f;
+		}
 	}
 	t = tic();
 	for ( i = 0; i < iterations; i++ ) {