Fix typo in linker section of docs.

Change-Id: If32fd31417e02f5ab49c4f2168b020215c348264
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/6001
Reviewed-by: Brett Wilson <brettw@chromium.org>
Commit-Queue: Brett Wilson <brettw@chromium.org>

tools/gn/functions.cc

diff --git a/tools/gn/functions.cc b/tools/gn/functions.cc
index ad4a1b6..05033c8 100644
--- a/tools/gn/functions.cc
+++ b/tools/gn/functions.cc
@@ -911,7 +911,7 @@
   toolchain("toolchain") {
     tool("link") {
       command = "..."
-      pool = ":link_pool($default_toolchain)")
+      pool = ":link_pool($default_toolchain)"
     }
   }
 )*";