some fuzz hacking

fuzz/FuzzPaeth.cpp

Index: fuzz/FuzzPaeth.cpp
diff --git a/fuzz/FuzzPaeth.cpp b/fuzz/FuzzPaeth.cpp
index aa7deb09e2bed1651b883af3aad322d192f01f8e..d7c139ce7a32d4cfa34bc97fee799af29124e5d4 100644
--- a/fuzz/FuzzPaeth.cpp
+++ b/fuzz/FuzzPaeth.cpp
@@ -33,8 +33,8 @@ static uint8_t paeth_alt(uint8_t a, uint8_t b, uint8_t c) {
 }
 
 DEF_FUZZ(Paeth, fuzz) {
-    int a = fuzz->nextU(),
-        b = fuzz->nextU(),
-        c = fuzz->nextU();
+    auto a = fuzz->nextB(),
+         b = fuzz->nextB(),
+         c = fuzz->nextB();
     ASSERT(paeth_alt(a,b,c) == paeth_std(a,b,c));
 }