kernel/watchdog: Initialize 'result'

Variable on the stack is not initialized to zero, do it
explicitly.

This bug was found by a compiler warning:

 kernel/watchdog.c:463: warning: 'result' may be used uninitialized in this function

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1278316854-28442-1-git-send-email-segooon@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>