Kernel: Don't take debug logging lock in sprintf()

This function doesn't write to the log, and so doesn't need to acquire
the logging lock. (This is only used by GCC's name demangling thingy.)

Kernel/kprintf.cpp

@@ -105,7 +105,6 @@ extern "C" int sprintf(char* buffer, const char* fmt, ...);
 
 int sprintf(char* buffer, const char* fmt, ...)
 {
-    ScopedSpinLock lock(s_log_lock);
     va_list ap;
     va_start(ap, fmt);
     int ret = printf_internal(buffer_putch, buffer, fmt, ap);