powerpc/process: Replace #ifdef CONFIG_KALLSYMS by IS_ENABLED()

The #ifdef CONFIG_KALLSYMS encloses some printk which can
compile in all cases.

Replace by IS_ENABLED().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2d89732a9062b2cf2651728804e4b8f6c9b9358e.1597643164.git.christophe.leroy@csgroup.eu

arch/powerpc/kernel/process.c

@@ -1525,14 +1525,14 @@ void show_regs(struct pt_regs * regs)
 			break;
 	}
 	pr_cont("\n");
-#ifdef CONFIG_KALLSYMS
 	/*
 	 * Lookup NIP late so we have the best change of getting the
 	 * above info out without failing
 	 */
-	printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
-	printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
-#endif
+	if (IS_ENABLED(CONFIG_KALLSYMS)) {
+		printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
+		printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
+	}
 	show_stack(current, (unsigned long *) regs->gpr[1], KERN_DEFAULT);
 	if (!user_mode(regs))
 		show_instructions(regs);