chore: address commit comment

PR-URL: #5736
Closes: #5719

Reviewed-by: Philipp Burckhardt <pburckhardt@outlook.com>

Author: jalajk3004

lib/node_modules/@stdlib/stats/base/dists/geometric/variance/README.md

@@ -154,7 +154,7 @@ Returns the [variance][variance] of a [geometric][geometric-distribution] distri
 
 ```c
 double out = stdlib_base_dists_geometric_variance( 0.5 );
-// returns 2
+// returns 2.0
 ```
 
 The function accepts the following arguments: