Revert "wifi: ath6k: silence false positive -Wno-dangling-pointer warning on GCC 12"

This reverts commit bd1d129d.

The dangling-pointer warnings were disabled kernel-wide by commit 49beadbd
("gcc-12: disable '-Wdangling-pointer' warning for now") for v5.19. So this
hack in ath6kl is not needed anymore.
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230724100823.2948804-1-kvalo@kernel.org

drivers/net/wireless/ath/ath6kl/Makefile

@@ -36,11 +36,6 @@ ath6kl_core-y += wmi.o
 ath6kl_core-y += core.o
 ath6kl_core-y += recovery.o
 
-# FIXME: temporarily silence -Wdangling-pointer on non W=1+ builds
-ifndef KBUILD_EXTRA_WARN
-CFLAGS_htc_mbox.o += $(call cc-disable-warning, dangling-pointer)
-endif
-
 ath6kl_core-$(CONFIG_NL80211_TESTMODE) += testmode.o
 ath6kl_core-$(CONFIG_ATH6KL_TRACING) += trace.o