tools/workqueue/wq_dump.py: fix column alignment in node_nr/max_active section

tools/workqueue/wq_dump.py: fix column alignment in node_nr/max_active section

On larger machines with many CPUs, max_active values such as 2048
exceed the hardcoded minimum field width of 3 characters, causing the
header and data columns to misalign.

Widen the format specifiers to accommodate 4-digit values and
right-align each nr/max as a single string to keep the output compact.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>