Fix Chameleon diags SFP TX bias calculation error
Early versions of the digital diagnostic standard (SFF-8472)
used a scale factor of 1uA/AD Count for interpreting laser
bias current readings. SFF-8472 later changed the scale
factor to 2uA/AD Count. I used an old spec when I coded up
the diags. Now we verified the SFP we used for Chameleon
complies with the latest SFF-8472. So I need to change the
formula.

Change-Id: I6e323ddd7d80a06a5ddc4ca197a254d36d2a734c
1 file changed