torture: Simplify code, eliminate RCU_PERF_TEST_RUNNABLE

This commit applies the infamous IS_ENABLED() macro to eliminate a #ifdef.
It also eliminates the RCU_PERF_TEST_RUNNABLE Kconfig option in favor
of the already-existing rcuperf.perf_runnable kernel boot parameter.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
index 3cee0d8..afd174e 100644
--- a/kernel/rcu/rcuperf.c
+++ b/kernel/rcu/rcuperf.c
@@ -96,12 +96,7 @@
 #define MAX_MEAS 10000
 #define MIN_MEAS 100
 
-#if defined(MODULE) || defined(CONFIG_RCU_PERF_TEST_RUNNABLE)
-#define RCUPERF_RUNNABLE_INIT 1
-#else
-#define RCUPERF_RUNNABLE_INIT 0
-#endif
-static int perf_runnable = RCUPERF_RUNNABLE_INIT;
+static int perf_runnable = IS_ENABLED(MODULE);
 module_param(perf_runnable, int, 0444);
 MODULE_PARM_DESC(perf_runnable, "Start rcuperf at boot");
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b9cfdbf..cf6ddcd 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1307,22 +1307,6 @@
 	  Say M if you want the RCU performance tests to build as a module.
 	  Say N if you are unsure.
 
-config RCU_PERF_TEST_RUNNABLE
-	bool "performance tests for RCU runnable by default"
-	depends on RCU_PERF_TEST = y
-	default n
-	help
-	  This option provides a way to build the RCU performance tests
-	  directly into the kernel without them starting up at boot time.
-	  You can use /sys/module to manually override this setting.
-	  This /proc file is available only when the RCU performance
-	  tests have been built into the kernel.
-
-	  Say Y here if you want the RCU performance tests to start during
-	  boot (you probably don't).
-	  Say N here if you want the RCU performance tests to start only
-	  after being manually enabled via /sys/module.
-
 config RCU_TORTURE_TEST
 	tristate "torture tests for RCU"
 	depends on DEBUG_KERNEL