design/40307-fuzzing.md: update example functions

Hope this syntax looks good :)

Thanks for this cool proposal!

Change-Id: I3fa04ca8f8b88b62f8a4a5b556a611f825c6ac3c
GitHub-Last-Rev: b2ca18c59b65a0a9719c953a63e710deda8f4d4e
GitHub-Pull-Request: golang/proposal#25
Reviewed-on: https://go-review.googlesource.com/c/proposal/+/244058
Reviewed-by: Katie Hockman <katie@golang.org>
diff --git a/design/40307-fuzzing.md b/design/40307-fuzzing.md
index bfa92dd..6d12ebe 100644
--- a/design/40307-fuzzing.md
+++ b/design/40307-fuzzing.md
@@ -372,7 +372,7 @@
 `myString`, and a `*big.Int`
 
 ```
-Fuzz(func(f *testing.F, a string, b myString, num *big.Int)
+f.Fuzz(func(a string, b myString, num *big.Int) { ... })
 ```
 
 There are three “units” that will need to be provided by the mutator, so three
@@ -385,7 +385,7 @@
 2:  A fuzz target’s `f.Fuzz` function takes one argument, a single `[]byte`
 
 ```
-Fuzz(func(f *testing.F, b []byte)
+f.Fuzz(func(b []byte) { ... })
 ```
 
 This is the typical “non-structured fuzzing” approach, and one that many