UPSTREAM: wifi: cfg80211: set country_elem to NULL

The link loop will always have a valid link so that
it's always set, but static checkers don't always
see that, so set it to NULL explicitly.

Fixes: efbabc11 ("cfg80211: Indicate MLO connection info in connect and roam callbacks")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Bug: 253289327
Change-Id: I6e904f9645e6cd63f67a2dbd14b14b59ee2690b8
(cherry picked from commit e3d331c9)
Signed-off-by: Kiran Kumar Lokere <quic_klokere@quicinc.com>
Signed-off-by: Veerendranath Jakkam <quic_vjakkam@quicinc.com>