[compiler-rt] Fix -Wformat in timing.h (NFC)

[compiler-rt] Fix -Wformat in timing.h (NFC)

/home/jiefu/llvm-project/compiler-rt/lib/scudo/standalone/timing.h:181:41: error: format specifies type 'unsigned long long' but the argument has type 'u64' (aka 'unsigned long') [-Werror,-Wformat]
    Str.append("%14llu.%llu(ns) %-11s", Integral, Fraction, " ");
                ~~~~~~                  ^~~~~~~~
                %14lu
/home/jiefu/llvm-project/compiler-rt/lib/scudo/standalone/timing.h:181:51: error: format specifies type 'unsigned long long' but the argument has type 'u64' (aka 'unsigned long') [-Werror,-Wformat]
    Str.append("%14llu.%llu(ns) %-11s", Integral, Fraction, " ");
                       ~~~~                       ^~~~~~~~
                       %lu
/home/jiefu/llvm-project/compiler-rt/lib/scudo/standalone/timing.h:185:54: error: format specifies type 'unsigned long long' but the argument has type 'u64' (aka 'unsigned long') [-Werror,-Wformat]
    Str.append("%s (%llu)\n", Timers[HandleId].Name, Occurrence);
                    ~~~~                             ^~~~~~~~~~
                    %lu
3 errors generated.