x86/pmem: Fix platform-device leak in error path

x86/pmem: Fix platform-device leak in error path

BugLink: https://bugs.launchpad.net/bugs/1990162
[ Upstream commit 229e73d46994f15314f58b2d39bf952111d89193 ]

Make sure to free the platform device in the unlikely event that
registration fails.

Fixes: 7a67832c7e44 ("libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220620140723.9810-1-johan@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>