Reformat imports to a consistent style for imports

rustfmt.toml configuration:
  imports_granularity = "One"
  group_imports = "One"

runtime/src/hardened_unpack.rs

@@ -1,9 +1,8 @@
-use solana_sdk::genesis_config::{DEFAULT_GENESIS_ARCHIVE, DEFAULT_GENESIS_FILE};
 use {
     bzip2::bufread::BzDecoder,
     log::*,
     rand::{thread_rng, Rng},
-    solana_sdk::genesis_config::GenesisConfig,
+    solana_sdk::genesis_config::{GenesisConfig, DEFAULT_GENESIS_ARCHIVE, DEFAULT_GENESIS_FILE},
     std::{
         collections::HashMap,
         fs::{self, File},
@@ -474,9 +473,11 @@ fn is_valid_genesis_archive_entry(parts: &[&str], kind: tar::EntryType) -> bool
 
 #[cfg(test)]
 mod tests {
-    use super::*;
-    use assert_matches::assert_matches;
-    use tar::{Builder, Header};
+    use {
+        super::*,
+        assert_matches::assert_matches,
+        tar::{Builder, Header},
+    };
 
     #[test]
     fn test_archive_is_valid_entry() {