remove all #include <blk.h>'s

Hi Linus,

the attached patch against 2.5.70 (gzip'ed due to it's size) causes blk.h to print a warning and removes all uses of blk.h. I've tested the compilation in 2.5.70 with a .config that tries to compile as much drivers as possible.

Please either apply it or send a short note that you don't want to apply it.

TIA
Adrian

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed