usb: gadget: lpc32xx_udc: fix clock imbalance in error path

usb: gadget: lpc32xx_udc: fix clock imbalance in error path

A recent change fixing a device reference leak introduced a clock
imbalance by reusing an error path so that the clock may be disabled
before having been enabled.

Note that the clock framework allows for passing in NULL clocks so there
is no risk for a NULL pointer dereference.

Also drop the bogus I2C client NULL check added by the offending commit
as the pointer has already been verified to be non-NULL.

Fixes: c84117912bdd ("USB: lpc32xx_udc: Fix error handling in probe")
Cc: stable@vger.kernel.org
Cc: Ma Ke <make24@iscas.ac.cn>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Link: https://patch.msgid.link/20251218153519.19453-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>