Note: The storage location returned can be a directory that does not exist; i.e., it may need to be created by the system or the user.
For linux, QStandardPath read the ~/.config/user-dirs.dirs to get the QStandardPaths::DesktopLocation path and the returned path may not exist, so we need manually check / create the path first.
Fix https://github.com/linuxdeepin/deepin-screenshot/issues/54
from: QStandardPaths::writableLocation:
For linux,
QStandardPathread the~/.config/user-dirs.dirsto get theQStandardPaths::DesktopLocationpath and the returned path may not exist, so we need manually check / create the path first.