ANDROID: Incremental fs: Fix scheduling while atomic error

If an incfs file is created, then the file system is sync'd,on opening
the incfs file inode_set reads the size from the backing file from
within iget5_locked, causing this error.

Test: incfs_test passes, this no longer occurs
Bug: 156413528
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Change-Id: I8939c4afa514d39d251c044d7680cfc69272669e