i2c-mpc.c driver issues

[Tjernlund]

While browsing the i2c-mpc.c driver I noticed some things that look odd
to me so I figured I report them. Could not find a maintainer in the MAINTANERS file
so I sent here, cc:ed linuxppc-dev as well.

1) There are a lot of return -1 error code that is propagated back to
   userspace. Should be changed to proper -Exxx codes.

2) mpc_read(), according to the comment below it sends a STOP condition here but
   this function does not known if this is the last read or not. mpc_xfer is
   the one that knows when the transaction is over and should send the stop, which it already
   does.

 /* Generate stop on last byte */
  if (i == length - 1)
       writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_TXAK);

 Jocke