eina_array: interpret the count of a NULL array as 0

this makes the usage way more convinient.

Reviewed-by: Xavi Artigas <xavierartigas@yahoo.es>
Differential Revision: https://phab.enlightenment.org/D11373

src/lib/eina/eina_inline_array.x

@@ -89,6 +89,7 @@ eina_array_count_get(const Eina_Array *array)
 static inline unsigned int
 eina_array_count(const Eina_Array *array)
 {
+   if (!array) return 0;
    return array->count;
 }