pinctrl: core: Set ret to 0 when group is skipped

mainline inclusion
from mainline-v5.13-rc1
commit 6a37d750
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60OLE
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6a37d750037827d385672acdebf5788fc2ffa633



--------------------------------

Static analyzer tool found that the ret variable is not initialized but
code expects ret value >=0 when pinconf is skipped in the first pinmux
loop. The same expectation is for pinmux in a pinconf loop.
That's why initialize ret to 0 to avoid uninitialized ret value in first
loop or reusing ret value from first loop in second.

Addresses-Coverity: ("Uninitialized variables")
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/e5203bae68eb94b4b8b4e67e5e7b4d86bb989724.1615534291.git.michal.simek@xilinx.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Yuyao Lin <linyuyao1@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>