[PATCH] binfmt_elf.c : fix checks for bad address

[PATCH] binfmt_elf.c : fix checks for bad address

Fix check for bad address; use macro instead of open-coding two checks.

Explanation from Ernie Petries in 2.6 commit :

  For background, the BAD_ADDR() macro should return TRUE if the address is
  TASK_SIZE, because that's the lowest address that is *not* valid for
  user-space mappings.  The macro was correct in binfmt_aout.c but was wrong
  for the "equal to" case in binfmt_elf.c.  There were two in-line validations
  of user-space addresses in binfmt_elf.c, which have been appropriately
  converted to use the corrected BAD_ADDR() macro in the patch you posted
  yesterday.  Note that the size checks against TASK_SIZE are okay as coded.

Note that this patch slightly differs from Ernie's in that the printk()
only got commented out instead of being removed, since a rate limited call
is expected soon.