runtime: fix typo in comment

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/140590043

diff --git a/src/runtime/mgc0.c b/src/runtime/mgc0.c
index 47659be266d8bb86de15b547c29b992ab85556ed..c976b09c36c8ffb81ee783d9e8624b63e51c83a0 100644 (file)
--- a/src/runtime/mgc0.c
+++ b/src/runtime/mgc0.c
@@ -997,7 +997,7 @@ runtime·MSpan_Sweep(MSpan *s, bool preserve)
 }
 
 // State of background runtime·sweep.
-// Pretected by runtime·gclock.
+// Protected by runtime·gclock.
 // Must match mgc0.go.
 struct
 {