Simplify branching logic

Author: kgryte

lib/node_modules/@stdlib/string/base/startcase/lib/main.js

@@ -46,14 +46,12 @@ function startcase( str ) {
 	for ( i = 0; i < str.length; i++ ) {
 		ch = str.charAt( i );
 		if ( reWhitespace.test( ch ) ) {
-			out += ch;
 			cap = true;
 		} else if ( cap ) {
-			out += ch.toUpperCase();
+			ch = ch.toUpperCase();
 			cap = false;
-		} else {
-			out += ch;
 		}
+		out += ch;
 	}
 	return out;
 }