ddr: altera: Internal mem_calibrate() cleanup part 5

ddr: altera: Internal mem_calibrate() cleanup part 5

This is kind of microseries-within-series indent cleanup.
Rework the code for the the middle-loop of the mega-loop
this time and deal with the group_failed variable. Instead
of checking if the group failed in the previous calibration
part, just jump to the end of the loop if calibration did
fail and increment the counter. This shaves away one more
level of indent while making the code slightly more readable.

It is likely that this patch has checkpatch warnings, but
for the sake of not breaking the code, these are ignored.

No functional change.

Signed-off-by: Marek Vasut <marex@denx.de>