path: fix slice OOB in trim

Internal function trim(arr). 2nd parameter of slice() should be slice's
end index (not included). Because of function normalize() (called before
trim()), "start" is always zero so the bug -for now- has no effect, but
its a bug waiting to happen.

Reviewed-by: Trevor Norris <trev.norris@gmail.com>

lib/path.js

@@ -269,7 +269,7 @@ if (isWindows) {
       }
 
       if (start > end) return [];
-      return arr.slice(start, end - start + 1);
+      return arr.slice(start, end + 1);
     }
 
     var toParts = trim(to.split('\\'));
@@ -413,7 +413,7 @@ if (isWindows) {
       }
 
       if (start > end) return [];
-      return arr.slice(start, end - start + 1);
+      return arr.slice(start, end + 1);
     }
 
     var fromParts = trim(from.split('/'));