Fix missing install

.github/workflows/fuzz.yml

@@ -8,7 +8,7 @@ on:
     types: [wf-fuzz]
 
 jobs:
-  bench:
+  fuzz:
     runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v1
@@ -32,6 +32,7 @@ jobs:
       - name: Build fuzz target
         working-directory: ./fuzz
         run: |
+          cargo install afl
           cargo afl build
 
       - name: Run fuzz