Add target_read_memory wrapper:

- replaces all calls to target->type->read_memory.
- add documentation in target_s to warn not to invoke callback directly.


git-svn-id: svn://svn.berlios.de/openocd/trunk@1959 b42882b7-edfa-0310-969c-e2dbd0fdcd60

src/flash/flash.c

@@ -1157,7 +1157,7 @@ int default_flash_mem_blank_check(struct flash_bank_s *bank)
 				chunk = (j - bank->sectors[i].size);
 			}
 
-			retval = target->type->read_memory(target, bank->base + bank->sectors[i].offset + j, 4, chunk/4, buffer);
+			retval = target_read_memory(target, bank->base + bank->sectors[i].offset + j, 4, chunk/4, buffer);
 			if (retval != ERROR_OK)
 				return retval;