runtime: rename gcController.findRunnable to findRunnableGCWorker

This avoids confusion with the main findrunnable in the scheduler.

Change-Id: I8cf40657557a8610a2fe5a2f74598518256ca7f0
Reviewed-on: https://go-review.googlesource.com/9305Reviewed-by: Rick Hudson <rlh@golang.org>

src/runtime/mgc.go

@@ -464,9 +464,9 @@ func (c *gcControllerState) endCycle() {
 	c.workRatioAvg = workRatioWeight*workRatio + (1-workRatioWeight)*c.workRatioAvg
 }
 
-// findRunnable returns the background mark worker for _p_ if it
+// findRunnableGCWorker returns the background mark worker for _p_ if it
 // should be run. This must only be called when gcBlackenEnabled != 0.
-func (c *gcControllerState) findRunnable(_p_ *p) *g {
+func (c *gcControllerState) findRunnableGCWorker(_p_ *p) *g {
 	if gcBlackenEnabled == 0 {
 		throw("gcControllerState.findRunnable: blackening not enabled")
 	}

src/runtime/proc1.go

@@ -1598,7 +1598,7 @@ top:
 		}
 	}
 	if gp == nil && gcBlackenEnabled != 0 {
-		gp = gcController.findRunnable(_g_.m.p.ptr())
+		gp = gcController.findRunnableGCWorker(_g_.m.p.ptr())
 		if gp != nil {
 			resetspinning()
 		}