rcuperf: Consistently insert space between flag and message

A few rcuperf dmesg output messages have no space between the flag and
the start of the message. In contrast, every other messages consistently
supplies a single space.  This difference makes rcuperf dmesg output
hard to read and to mechanically parse.  This commit therefore fixes
this problem by modifying a pr_alert() call and PERFOUT_STRING() macro
function to provide that single space.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

kernel/rcu/rcuperf.c

@@ -52,7 +52,7 @@ MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.vnet.ibm.com>");
 
 #define PERF_FLAG "-perf:"
 #define PERFOUT_STRING(s) \
-	pr_alert("%s" PERF_FLAG s "\n", perf_type)
+	pr_alert("%s" PERF_FLAG " %s\n", perf_type, s)
 #define VERBOSE_PERFOUT_STRING(s) \
 	do { if (verbose) pr_alert("%s" PERF_FLAG " %s\n", perf_type, s); } while (0)
 #define VERBOSE_PERFOUT_ERRSTRING(s) \
@@ -400,9 +400,8 @@ rcu_perf_writer(void *arg)
 			sp.sched_priority = 0;
 			sched_setscheduler_nocheck(current,
 						   SCHED_NORMAL, &sp);
-			pr_alert("%s" PERF_FLAG
-				 "rcu_perf_writer %ld has %d measurements\n",
-				 perf_type, me, MIN_MEAS);
+			pr_alert("%s%s rcu_perf_writer %ld has %d measurements\n",
+				 perf_type, PERF_FLAG, me, MIN_MEAS);
 			if (atomic_inc_return(&n_rcu_perf_writer_finished) >=
 			    nrealwriters) {
 				schedule_timeout_interruptible(10);