mac80211: IBSS: avoid unneeded return value processing

when ieee80211_ibss_csa_beacon() fails, we return it's value.
When it succeeds, we basically copy it's value and also .. return it.

Just return it immediately, simplifying the code.

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
Link: https://lore.kernel.org/r/20190911141431.12498-1-koen.vandeputte@ncentric.com


Signed-off-by: Johannes Berg <johannes.berg@intel.com>