refactor: avoid duplicated logic

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

Author: kgryte

lib/node_modules/@stdlib/stats/base/variancech/lib/accessors.js

@@ -71,12 +71,6 @@ function variancech( N, correction, x, strideX, offsetX ) {
 	get = x.accessors[ 0 ];
 
 	n = N - correction;
-	if ( N <= 0 || n <= 0.0 ) {
-		return NaN;
-	}
-	if ( N === 1 || strideX === 0 ) {
-		return 0.0;
-	}
 	ix = offsetX;
 
 	// Use an estimate for the mean: