usb: typec: intel_pmc_mux: Zero initialize num_ports in pmc_usb_probe()

usb: typec: intel_pmc_mux: Zero initialize num_ports in pmc_usb_probe()

Clang warns (or errors with CONFIG_WERROR=y / W=e):

  drivers/usb/typec/mux/intel_pmc_mux.c:740:3: error: variable 'num_ports' is uninitialized when used here [-Werror,-Wuninitialized]
    740 |                 num_ports++;
        |                 ^~~~~~~~~

This should have been initialized to zero. Do so now to clean up the
warning and ensure num_ports does not use uninitialized memory.

Fixes: 8bdb0b3830ea ("usb: typec: intel_pmc_mux: combine kzalloc + kcalloc")
Reported-by: kernelci.org bot <bot@kernelci.org>
Closes: https://lore.kernel.org/177793914437.2560.9287713196857718000@997d03828cfd/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://patch.msgid.link/20260506-typec-intel_pmc_mux-fix-uninit-num_ports-v1-1-929b128a32e9@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>