x86/apic: Modernize the pending interrupt code

The pending interrupt check code is old, update the following:

  - Use for_each_set_bit() instead of open coding it
  - Replace printk() with pr_err()
  - Get rid of printk line breaks
  - Make curly braces balanced

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: bhe@redhat.com
Cc: ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20180301055930.2396-3-douly.fnst@cn.fujitsu.com

arch/x86/kernel/apic/apic.c

@@ -1412,7 +1412,8 @@ static void apic_pending_intr_clear(void)
 {
 	long long max_loops = cpu_khz ? cpu_khz : 1000000;
 	unsigned long long tsc = 0, ntsc;
-	unsigned int value, queued;
+	unsigned int queued;
+	unsigned long value;
 	int i, j, acked = 0;
 
 	if (boot_cpu_has(X86_FEATURE_TSC))
@@ -1435,24 +1436,22 @@ static void apic_pending_intr_clear(void)
 
 		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
 			value = apic_read(APIC_ISR + i*0x10);
-			for (j = 31; j >= 0; j--) {
-				if (value & (1<<j)) {
-					ack_APIC_irq();
-					acked++;
-				}
+			for_each_set_bit(j, &value, 32) {
+				ack_APIC_irq();
+				acked++;
 			}
 		}
 		if (acked > 256) {
-			printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n",
-			       acked);
+			pr_err("LAPIC pending interrupts after %d EOI\n", acked);
 			break;
 		}
 		if (queued) {
 			if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) {
 				ntsc = rdtsc();
 				max_loops = (cpu_khz << 10) - (ntsc - tsc);
-			} else
+			} else {
 				max_loops--;
+			}
 		}
 	} while (queued && max_loops > 0);
 	WARN_ON(max_loops <= 0);