use defines in sys_getpriority/sys_setpriority

Switch to the defines for these two checks, instead of hard coding the
values.

[akpm@linux-foundation.org: add missing include]
Signed-off-by: NDaniel Walker <dwalker@mvista.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/sys.c

@@ -14,6 +14,7 @@
 #include <linux/prctl.h>
 #include <linux/highuid.h>
 #include <linux/fs.h>
+#include <linux/resource.h>
 #include <linux/kernel.h>
 #include <linux/kexec.h>
 #include <linux/workqueue.h>
@@ -659,7 +660,7 @@ asmlinkage long sys_setpriority(int which, int who, int niceval)
 	int error = -EINVAL;
 	struct pid *pgrp;
 
-	if (which > 2 || which < 0)
+	if (which > PRIO_USER || which < PRIO_PROCESS)
 		goto out;
 
 	/* normalize: avoid signed division (rounding problems) */
@@ -723,7 +724,7 @@ asmlinkage long sys_getpriority(int which, int who)
 	long niceval, retval = -ESRCH;
 	struct pid *pgrp;
 
-	if (which > 2 || which < 0)
+	if (which > PRIO_USER || which < PRIO_PROCESS)
 		return -EINVAL;
 
 	read_lock(&tasklist_lock);