Skip FDE-specific operations, mkdir() throwing.

vold already complains about calls that are FDE specific, which
results in a lot of wtf() noise, so skip those operations outright.

Throw from failed mkdir() back to caller instead of wtf().

Test: builds, boots
Bug: 68736572, 68736551
Change-Id: I4dc06bdedacd2b66a1e7ae8e1434b194a875a756
4 files changed