build: remove temporary -Wno-error=bool-operation

crrev.com/c/1846084 temporarily added -Wno-error=bool-operation to
prevent builds from failing on a newly introduced Clang warning.
The code that triggered the warning has now been fixed, so we can
stop suppressing the error.

Bug: 1011810
Change-Id: I3d3818ae4805642e96bdcc19cff83a7ef5cf397f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1845484Reviewed-by: Reid Kleckner <rnk@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703975}

build/config/compiler/BUILD.gn

@@ -1538,13 +1538,6 @@ config("default_warnings") {
           # TODO(https://crbug.com/995993): Clean up and enable.
           "-Wno-implicit-fallthrough",
         ]
-
-        if (llvm_force_head_revision) {
-          cflags += [
-            # TODO(https://crbug.com/1011810): Re-enable once fix is in.
-            "-Wno-error=bool-operation",
-          ]
-        }
       }
     }
   }