Right now, 'iw phy ... reg get' gets translated to NLM_F_DUMP, which
dumps all domains. But this command really is looking for non-DUMP
semantics -- it only wants the domain for the specified wiphy, or (per
the kernel's choice) the global, if the wiphy doesn't have its own.
We can achieve this by skipping the handle_reg_get() -> "reg dump"
indirection.
[ with a wiphy-specific domain ]
Before:
# iw phy phy0 reg get
global
country XX: DFS-YYY
[...]
phy#0
country AA: DFS-BBB
[...]
After:
# iw phy phy0 reg get
phy#0
country AA: DFS-BBB
[...]
[ without a wiphy-specific domain ]
Before and after (unchanged):
# iw phy phy0 reg get
global
country XX: DFS-YYY
[...]