fireball: change fstab storage to wildcard match

Prefix pattern matching is deprecated, update to wildcard. Fixes the
following: W/DirectVolume(  156): Deprecated implied prefix pattern
detected, please use '/devices/platform/msm_sdcc.1/mmc_host/mmc0*'
instead.

Change-Id: Ic5caa57d4c3b98625404bada08dec589210f07bc