sdcardfs: fix wrong ENOENT when creating a file

There is subtle race condtion where lower_dentry is null. If we retry
lookup again, we should get the correct dentry.

Bug: 110585947
Bug: 110464178
Bug: 80587794
Bug: 37231161
Bug: 110199687
Change-Id: I39b95de4649b034287776f5c8a5d197b6ebd9ada
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
Signed-off-by: Jprimero15 <jprimero155@gmail.com>