fuzz: fix the generic-fuzz-floppy config

On the pc-i440fx machine, the floppy drive relies on the i8257 DMA
controller. Add this device to the floppy fuzzer config, and silence the
warning about a missing format specifier for the null-co:// drive.

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Message-Id: <20201216203328.41112-1-alxndr@bu.edu>
Signed-off-by: Thomas Huth <thuth@redhat.com>

tests/qtest/fuzz/generic_fuzz_configs.h

@@ -92,9 +92,9 @@ const generic_fuzz_config predefined_configs[] = {
     },{
         .name = "floppy",
         .args = "-machine pc -nodefaults -device floppy,id=floppy0 "
-        "-drive id=disk0,file=null-co://,file.read-zeroes=on,if=none "
+        "-drive id=disk0,file=null-co://,file.read-zeroes=on,if=none,format=raw "
         "-device floppy,drive=disk0,drive-type=288",
-        .objects = "fd* floppy*",
+        .objects = "fd* floppy* i8257",
     },{
         .name = "xhci",
         .args = "-machine q35 -nodefaults "