page_alloc: remove inactive initialization

The allocation address of the table pointer variable is first performed in
the function, no initialization assignment is required, and no invalid
pointer will appear.

Link: https://lkml.kernel.org/r/20220803064118.3664-1-kunyu@nfschina.com


Signed-off-by: Li kunyu <kunyu@nfschina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>