phy: stm32: fix a refcount leak in stm32_usbphyc_pll_enable()

This error path needs to decrement "usbphyc->n_pll_cons.counter" before
returning.

Fixes: 5b1af712 ("phy: stm32: rework PLL Lock detection")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220112111724.GB3019@kili


Signed-off-by: Vinod Koul <vkoul@kernel.org>