lockup_detector: Make callback function static
lockup_detector: Make callback function static

watchdog_overflow_callback() is only used in kernel/watchdog.c.

Signed-off-by: Lin Ming <d6f051473f553588884d51874952f6fb19ae8261@intel.com>
Cc: Peter Zijlstra <3fddac958924aef220f202ca567388ddab3f14a8@infradead.org>
Cc: Don Zickus <3c9a8cec2f33672bf03519b05ce2324e6cf5717a@redhat.com>
LKML-Reference: <d5804aaedbae33caccd3d72edb6a89eec49b73da@minggr.sh.intel.com>
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs