fix tests

Author: RalfJung

test-cargo-miri/test.stdout.ref

@@ -5,10 +5,9 @@ test test::rng ... ok
 test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
 
 
-running 3 tests
+running 2 tests
 test entropy_rng ... ok
-test fixed_rng ... ok
 test simple ... ok
 
-test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
+test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
 

test-cargo-miri/test.stdout.ref2

@@ -7,5 +7,5 @@ test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 1 filtered out
 running 1 test
 test simple ... ok
 
-test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 2 filtered out
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 1 filtered out
 

test-cargo-miri/tests/test.rs

@@ -1,4 +1,4 @@
-use rand::{SeedableRng, FromEntropy, Rng, rngs::SmallRng};
+use rand::{FromEntropy, Rng, rngs::SmallRng};
 
 // Having more than 1 test does seem to make a difference
 // (i.e., this calls ptr::swap which having just one test does not).