remove generic_block_fiemap

Hi all,

this series removes the get_block-based generic_block_fiemap helper
by switching the last two users to use the iomap version instead.

The ext2 version has been tested using xfstests, but the hpfs one
is only compile tested due to the lack of easy to run tests.

diffstat:
 fs/ext2/inode.c        |   15 +--
 fs/hpfs/file.c         |   51 ++++++++++++
 fs/ioctl.c             |  203 -------------------------------------------------
 include/linux/fiemap.h |    4 
 4 files changed, 58 insertions(+), 215 deletions(-)