[PATCH] net: wwan: t7xx: do not compile with -Werror by default

["Jiri Slaby (SUSE)" <jirislaby@kernel.org>]

When playing with various compilers or their versions, some choke on
the t7xx code. For example (with gcc 13):
 In file included from ./arch/s390/include/generated/asm/rwonce.h:1,
                  from ../include/linux/compiler.h:247,
                  from ../include/linux/build_bug.h:5,
                  from ../include/linux/bits.h:22,
                  from ../drivers/net/wwan/t7xx/t7xx_state_monitor.c:17:
 In function 'preempt_count',
     inlined from 't7xx_fsm_append_event' at ../drivers/net/wwan/t7xx/t7xx_state_monitor.c:439:43:
 ../include/asm-generic/rwonce.h:44:26: error: array subscript 0 is outside array bounds of 'const volatile int[0]' [-Werror=array-bounds=]

There is no reason for any code in the kernel to be built with -Werror
by default. Note that we have generic CONFIG_WERROR. OTOH, some drivers
may want to do this only on per-driver basis. Some do
CONFIG_DRM_I915_WERROR or alike. But I reused the scsi's:
  ifdef WARNINGS_BECOME_ERRORS
approach.

Now, if one wants to build t7xx with -Werror, they may say:
  make WARNINGS_BECOME_ERRORS=1

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
Cc: Intel Corporation <linuxwwan@intel.com>
Cc: Chiranjeevi Rapolu <chiranjeevi.rapolu@linux.intel.com>
Cc: Liu Haijun <haijun.liu@mediatek.com>
Cc: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Cc: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Cc: Loic Poulain <loic.poulain@linaro.org>
Cc: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
---
 drivers/net/wwan/t7xx/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/wwan/t7xx/Makefile b/drivers/net/wwan/t7xx/Makefile
index 268ff9e87e5b..29622c2c4533 100644
--- a/drivers/net/wwan/t7xx/Makefile
+++ b/drivers/net/wwan/t7xx/Makefile
@@ -1,6 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
+ifdef WARNINGS_BECOME_ERRORS
 ccflags-y += -Werror
+endif
 
 obj-${CONFIG_MTK_T7XX} := mtk_t7xx.o
 mtk_t7xx-y:=	t7xx_pci.o \
-- 
2.40.0