internal/ethapi: fix state override test (#30228)

Looks like #30094 became a bit stale after #30185 was merged and now we
have a stale ref to a state override object causing CI to fail on
master.

internal/ethapi/api_test.go

@@ -979,7 +979,7 @@ func TestCall(t *testing.T) {
 			},
 			overrides: StateOverride{
 				dad: OverrideAccount{
-					State: &map[common.Hash]common.Hash{},
+					State: map[common.Hash]common.Hash{},
 				},
 			},
 			want: "0x0000000000000000000000000000000000000000000000000000000000000000",