1. provide VfsMpFind which doesn't support mounting recursively;
2. provide a macro to set whether supporting recursive-mount or not.
3. adding path length checking
BREAKING CHANGE:
new config option:
LOSCFG_FS_SUPPORT_MOUNT_TARGET_RECURSIVE
fix #I677ZT
Signed-off-by: Far <yesiyuan2@huawei.com>
Change-Id: I92a752fe2bcdd2b036630b5e4e8d7df1562629e0