binder: remove repeat word from comment

binder.c file comment produce warning with checkpatch as below:
WARNING: Possible repeated word: 'for'
Remove the repeated word from the comment avoid this warning.

Signed-off-by: Ajith P V <ajithpv.linux@gmail.com>
Link: https://lore.kernel.org/r/20211125122218.6767-1-ajithpv.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>