driver core: platform: Drop redundant check in platform_device_add()

driver core: platform: Drop redundant check in platform_device_add()

Starting from the commit 37c12e7497b6 ("[DRIVER MODEL] Improved
dynamically allocated platform_device interface") the pdev expects
to be allocated beforehand or guaranteed to be non-NULL.

Hence the leftover check is now redundant (as we have no combined
calls like platform_device_add(platform_device_alloc(...)) in the
entire kernel source code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20231003142122.3072824-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>