MIPS: Get rid of 'kgdb_early_setup' cruft.

Commit 854700115ecf ([MIPS] kgdb: add arch support for the kernel's kgdb core)
added the 'kgdb_early_setup' flag to avoid calling trap_init() and init_IRQ()
the second time, however the code that called these functions earlier, from
kgdb_arch_init(), had been already removed by that time, so the flag never
served any useful purpose. Remove the related code along with ugly #ifdef'ery
at last.

[[e-mail]: Folded in Guenter Roeck's fix.]

Signed-off-by: Sergei Shtylyov <[e-mail]>
Patchwork: https://patchwork.linux-mips.org/patch/10501/
Signed-off-by: Guenter Roeck <[e-mail]>
Patchwork: https://patchwork.linux-mips.org/patch/10533/
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/include/asm/kgdb.h

···
 #define CACHE_FLUSH_IS_SAFE	0
 
 extern void arch_kgdb_breakpoint(void);
-extern int kgdb_early_setup;
 extern void *saved_vectors[32];
 extern void handle_exception(struct pt_regs *regs);
 extern void breakinst(void);

arch/mips/kernel/irq.c

···
 #include <linux/atomic.h>
 #include <asm/uaccess.h>
 
-#ifdef CONFIG_KGDB
-int kgdb_early_setup;
-#endif
-
 static DECLARE_BITMAP(irq_map, NR_IRQS);
 
 int allocate_irqno(void)
···
 {
 	int i;
 
-#ifdef CONFIG_KGDB
-	if (kgdb_early_setup)
-		return;
-#endif
-
 	for (i = 0; i < NR_IRQS; i++)
 		irq_set_noprobe(i);
 
 	arch_init_irq();
-
-#ifdef CONFIG_KGDB
-	if (!kgdb_early_setup)
-		kgdb_early_setup = 1;
-#endif
 }
 
 #ifdef CONFIG_DEBUG_STACKOVERFLOW

arch/mips/kernel/kgdb.c

···
 
 struct kgdb_arch arch_kgdb_ops;
 
-/*
- * We use kgdb_early_setup so that functions we need to call now don't
- * cause trouble when called again later.
- */
 int kgdb_arch_init(void)
 {
 	union mips_instruction insn = {

arch/mips/kernel/traps.c

···
 
 	check_wait();
 
-#if defined(CONFIG_KGDB)
-	if (kgdb_early_setup)
-		return; /* Already done */
-#endif
-
 	if (cpu_has_veic || cpu_has_vint) {
 		unsigned long size = 0x200 + VECTORSPACING*64;
 		ebase = (unsigned long)