recovery: Address the ioctl denials during wiping.

avc:  denied  { ioctl } for  pid=599 comm="mke2fs" path="/dev/block/sda13" dev="tmpfs" ino=18975 ioctlcmd=127b scontext=u:r:recovery:s0 tcontext=u:object_r:userdata_block_device:s0 tclass=blk_file
avc:  denied  { ioctl } for  pid=587 comm="mke2fs" path="/dev/block/sda20" dev="tmpfs" ino=17931 ioctlcmd=0x127b scontext=u:r:recovery:s0 tcontext=u:object_r:metadata_block_device:s0 tclass=blk_file

0x127b (BLKPBSZGET) is called by mke2fs that queries physical sector
size. Although the denial is currently non-fatal, as mke2fs falls back
to use logical sector size, it might lead to undesired result in future.

Test: Factory reset on taimen and blueline respectively.
Change-Id: I14fc6593aeae309c79f5eadcffc8158b0a2ab2f6