libbinder Parcel: Fix ubsan error in readData

Use don't cast the result of readInplace before calling memcpy to align
the data. With clang-r522817 passing an unaligned pointer to memcpy also
triggers a ubsan error.

Bug: 354981705
Change-Id: Ibd104bcfac519211857f1e9e93a1ec35e7bcd773