hw/misc/arm_sysctl.c: Avoid shadowing local variable

hw/misc/arm_sysctl.c: Avoid shadowing local variable

Avoid shadowing a local variable in arm_sysctl_write():

../../hw/misc/arm_sysctl.c: In function ‘arm_sysctl_write’:
../../hw/misc/arm_sysctl.c:537:26: warning: declaration of ‘val’ shadows a parameter [-Wshadow=local]
  537 |                 uint32_t val;
      |                          ^~~
../../hw/misc/arm_sysctl.c:388:39: note: shadowed declaration is here
  388 |                              uint64_t val, unsigned size)
      |                              ~~~~~~~~~^~~

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-ID: <20230922152944.3583438-3-peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>