MIPS: traps: Fix output of show_stacktrace

Since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing
continuation lines") the output from show_stacktrace on MIPS has been
pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to
provide the appropriate markers & restore the expected output. Also
start a new line with printk such that the presence of timing
information does not interfere with output.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14430/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/traps.c

@@ -174,22 +174,24 @@ static void show_stacktrace(struct task_struct *task,
 	printk("Stack :");
 	i = 0;
 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
-		if (i && ((i % (64 / field)) == 0))
-			printk("\n	 ");
+		if (i && ((i % (64 / field)) == 0)) {
+			pr_cont("\n");
+			printk("       ");
+		}
 		if (i > 39) {
-			printk(" ...");
+			pr_cont(" ...");
 			break;
 		}
 
 		if (__get_user(stackdata, sp++)) {
-			printk(" (Bad stack address)");
+			pr_cont(" (Bad stack address)");
 			break;
 		}
 
-		printk(" %0*lx", field, stackdata);
+		pr_cont(" %0*lx", field, stackdata);
 		i++;
 	}
-	printk("\n");
+	pr_cont("\n");
 	show_backtrace(task, regs);
 }