UPSTREAM: wireguard: do not use -O3

Apparently, various versions of gcc have O3-related miscompiles. Looking
at the difference between -O2 and -O3 for gcc 11 doesn't indicate
miscompiles, but the difference also doesn't seem so significant for
performance that it's worth risking.

Bug: 254441685
Link: https://lore.kernel.org/lkml/CAHk-=wjuoGyxDhAF8SsrTkN0-YfCx7E6jUN3ikC_tn2AKWTTsA@mail.gmail.com/
Link: https://lore.kernel.org/lkml/CAHmME9otB5Wwxp7H8bR_i2uH2esEMvoBMC8uEXBMH9p0q1s6Bw@mail.gmail.com/
Reported-by: Linus Torvalds <[email protected]>
Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Cc: [email protected]
Signed-off-by: Jason A. Donenfeld <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
(cherry picked from commit cc5060ca0285efe2728bced399a1955a7ce808b2)
Signed-off-by: Lee Jones <[email protected]>
Change-Id: Ie6971cdfe76e6c06c1f068316c64e28a362c057f

Author: zx2c4

drivers/net/wireguard/Makefile

@@ -2,8 +2,7 @@
 #
 # Copyright (C) 2015-2019 Jason A. Donenfeld <[email protected]>. All Rights Reserved.
 
-ccflags-y := -O3
-ccflags-y += -D'pr_fmt(fmt)=KBUILD_MODNAME ": " fmt'
+ccflags-y := -D'pr_fmt(fmt)=KBUILD_MODNAME ": " fmt'
 ccflags-$(CONFIG_WIREGUARD_DEBUG) += -DDEBUG
 wireguard-y := main.o
 wireguard-y += noise.o