workqueue: avoid clang warning

workqueue: avoid clang warning

Building with clang shows lots of warning like:

drivers/amba/bus.c:447:8: warning: implicit conversion from 'long long' to 'int' changes value from 4294967248 to -48
      [-Wconstant-conversion]
static DECLARE_DELAYED_WORK(deferred_retry_work, amba_deferred_retry_func);
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/workqueue.h:187:26: note: expanded from macro 'DECLARE_DELAYED_WORK'
        struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/workqueue.h:177:10: note: expanded from macro '__DELAYED_WORK_INITIALIZER'
        .work = __WORK_INITIALIZER((n).work, (f)),                      \
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/workqueue.h:170:10: note: expanded from macro '__WORK_INITIALIZER'
        .data = WORK_DATA_STATIC_INIT(),                                \
                ^~~~~~~~~~~~~~~~~~~~~~~
include/linux/workqueue.h:111:39: note: expanded from macro 'WORK_DATA_STATIC_INIT'
        ATOMIC_LONG_INIT(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC)
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
include/asm-generic/atomic-long.h:32:41: note: expanded from macro 'ATOMIC_LONG_INIT'
 #define ATOMIC_LONG_INIT(i)     ATOMIC_INIT(i)
                                ~~~~~~~~~~~~^~
arch/arm/include/asm/atomic.h:21:27: note: expanded from macro 'ATOMIC_INIT'
 #define ATOMIC_INIT(i)  { (i) }
                        ~  ^

This makes the type cast explicit, which shuts up the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tejun Heo <tj@kernel.org>