irq.c: Replace old __unlikely with newlib standard macro

Author: QuzarDC

kernel/arch/dreamcast/kernel/irq.c

@@ -217,7 +217,7 @@ void irq_handle_exception(int code) {
     int handled = 0;
 
     if(__is_defined(__SH_ATOMIC_MODEL_SOFT_GUSA__)
-       && __unlikely((int32_t)irq_srt_addr->r[15] >= -128
+       && __predict_false((int32_t)irq_srt_addr->r[15] >= -128
                      && irq_srt_addr->pc != irq_srt_addr->r[0])) {
         /* The stack pointer has been altered: it means we are in the middle of
            an atomic section, and we need to roll-back.
@@ -458,4 +458,4 @@ void irq_set_priority(irq_src_t src, unsigned int prio) {
 
 unsigned int irq_get_priority(irq_src_t src) {
     return (REG_IPR(src / 4) >> (src % 4) * 4) & 0xf;
-}
+}