driver core: devtmpfs: fix compile failure with CONFIG_UIDGID_STRICT_TYPE_CHECKS

driver core: devtmpfs: fix compile failure with CONFIG_UIDGID_STRICT_TYPE_CHECKS

If CONFIG_UIDGID_STRICT_TYPE_CHECKS is enalbed, the below compile
failure will be triggered:

	drivers/base/devtmpfs.c: In function 'handle_create':
	drivers/base/devtmpfs.c:214:19: error: incompatible types when assigning to type 'kuid_t' from type 'uid_t'
	drivers/base/devtmpfs.c:215:19: error: incompatible types when assigning to type 'kgid_t' from type 'gid_t'
	make[2]: *** [drivers/base/devtmpfs.o] Error 1

This patch fixes the compile failure.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>