wifi: rtw89: fw: remove unnecessary rcu_read_unlock() for punctured

The rcu_read_unlock() is accidentally added, and sparse warn:

  drivers/net/wireless/realtek/rtw89/fw.c:2807:17:
    warning: context imbalance in 'rtw89_fw_h2c_assoc_cmac_tbl_g7' - unexpected unlock

Fixes: b82730bf ("wifi: cfg80211/mac80211: move puncturing into chandef")
Cc: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240213122556.9593-1-pkshih@realtek.com