pinctrl: core: fix possible memory leak in pinctrl_enable()

I got memory leak as follows when doing fault injection test:

unreferenced object 0xffff888020a7a680 (size 64):
  comm "i2c-mcp23018-41", pid 23090, jiffies 4295160544 (age 8.680s)
  hex dump (first 32 bytes):
    00 48 d3 1e 80 88 ff ff 00 1a 56 c1 ff ff ff ff  .H........V.....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<0000000083c79b35>] kmem_cache_alloc_trace+0x16d/0x360
    [<0000000051803c95>] pinctrl_init_controller+0x6ed/0xb70
    [<0000000064346707>] pinctrl_register+0x27/0x80
    [<0000000029b0e186>] devm_pinctrl_register+0x5b/0xe0
    [<00000000391f5a3e>] mcp23s08_probe_one+0x968/0x118a [pinctrl_mcp23s08]
    [<000000006112c039>] mcp230xx_probe+0x266/0x560 [pinctrl_mcp23s08_i2c]

If pinctrl_claim_hogs() fails, the 'pindesc' allocated in pinctrl_register_one_pin()
need be freed.

Cc: stable@vger.kernel.org
Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 950b0d91 ("pinctrl: core: Fix regression caused by delayed work for hogs")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20211022014323.1156924-1-yangyingliang@huawei.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/core.c

@@ -2100,6 +2100,8 @@ int pinctrl_enable(struct pinctrl_dev *pctldev)
 	if (error) {
 		dev_err(pctldev->dev, "could not claim hogs: %i\n",
 			error);
+		pinctrl_free_pindescs(pctldev, pctldev->desc->pins,
+				      pctldev->desc->npins);
 		mutex_destroy(&pctldev->mutex);
 		kfree(pctldev);