binder: remove redundant variable page_addr

Variable page_addr is being assigned a value that is never read. The
variable is redundant and can be removed.

Cleans up clang scan build warning:
warning: Value stored to 'page_addr' is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@intel.com>
Fixes: 162c7973

 ("binder: avoid user addresses in debug logs")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312060851.cudv98wG-lkp@intel.com/
Acked-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20240307221505.101431-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>