i2c: dev: fix potential memory leak in i2cdev_ioctl_rdwr

[ Upstream commit a0692f0eef91354b62c2b4c94954536536be5425 ]

If I2C_M_RECV_LEN check failed, msgs[i].buf allocated by memdup_user
will not be freed. Pump index up so it will be freed.

Fixes: 838bfa60 ("i2c-dev: Add support for I2C_M_RECV_LEN")
Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Change-Id: Ia4a4888ae6eb4b6b2a610700ab1facb29839ac86