Change prototype for bi_end_io

Hi Jens,
 here are a few more patches from my set that makes various changes to bio
 submission and handling.

 These change the ->bi_end_io prototype so that
   1/ no 'size' is passed
   2/ there is no return value.

 The 'size' is not really of interest to any bi_end_io handler in existance. 
 It is really only an internal detail to the "request" handling in ll_rw_blk
 and lower levels.
 The return value is completely unused.

 After these patches, ->bi_end_io is only ever called once per bio.

 Note that the last patch makes lots and lots of simple changes.  I
 think I have found all the right places, but any recently added
 device drivers might still be using the old bi_end_io prototype.
 I'll grep again after these patches are in your tree.

 That patches are against linux-block as of an hour ago.

Thanks,
NeilBrown

Net result of the 4 patches:

 46 files changed, 166 insertions(+), 385 deletions(-)


 [PATCH 001 of 4] Remove flush_dry_bio_endio
 [PATCH 002 of 4] Only call bi_end_io once for any bio.
 [PATCH 003 of 4] Don't decrement bi_size in bio_endio.
 [PATCH 004 of 4] Drop 'size' argument from bio_endio and bi_end_io.