Adjust function definitions in kern_dtrace.c to avoid clang 15 warnings
With clang 15, the following -Werror warnings are produced:
sys/kern/kern_dtrace.c:64:18: error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes] kdtrace_proc_size() ^ void sys/kern/kern_dtrace.c:87:20: error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes] kdtrace_thread_size() ^ void
This is because kdtrace_proc_size() and kdtrace_thread_size() are
declared with (void) argument lists, but defined with empty argument
lists. Make the definitions match the declarations.
MFC after: 3 days
(cherry picked from commit db8ea61ae261cc060f423dea050bf943bcad6793)