Bug report: PXE blocksize

[Turner, Ian]

Hello list,

There seem to be a couple of problems with this variable:

1. The variable name in the code is pxe_blksize, whereas the info file 
references net_pxe_blksize.
2. Changing the blocksize from within a config file which is itself sourced 
from TFTP breaks the transfer of the remainder of that file, because 
grub_pxe_read() references the grub_pxe_blksize variable at each packet.

Issue #2 can be resolved just by changing the grub_pxe_read() reference to 
grub_pxe_blksize to reference data->block_size instead.

This is in the newreloc branch.

Cheers,

--Ian