optimized memory usage when checking files fails

ChangeLog

@@ -57,6 +57,7 @@ release 0.14.4
 	  slash for multi-file torrents
 	* lowered the default connection speed to 10 connection attempts
 	  per second
+	* optimized memory usage when checking files fails
 
 release 0.14.3
 

src/storage.cpp

@@ -2453,7 +2453,10 @@ ret:
 #else
 				&& m_storage->error() != error_code(ENOENT, get_posix_category()))
 #endif
+			{
+				m_piece_data.reset();
 				return -1;
+			}
 			return skip_file();
 		}