Staging: android: fixed a space warning in binder.h

This patch fixes a simple tab-space warning in binder.h found by checkpatch tool

Change-Id: If5275dfa3c466a27d90c956e74af89531b3f2dd5
Signed-off-by: Marco Navarra <fromenglish@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>