Remove string copy

Changed 'ecma_copy_or_ref_ecma_string' to 'ecma_ref_ecma_string'. It does
not copy the string if the maximum number of reference counter is reached,
but bails out with an error like the 'ecma_ref_object' function does.

JerryScript-DCO-1.0-Signed-off-by: László Langó llango.u-szeged@partner.samsung.com

jerry-core/jerry.c

@@ -357,7 +357,7 @@ jerry_acquire_string (jerry_string_t *string_p) /**< pointer passed to function
 {
   jerry_assert_api_available ();
 
-  return ecma_copy_or_ref_ecma_string (string_p);
+  return ecma_ref_ecma_string (string_p);
 } /* jerry_acquire_string */
 
 /**