rust: remove dependency on itertools

The only use for itertools is in parse_mount_options() where we take a
vector, convert it to iterator and then join it. Instead, we can join
the vector directly.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

rust-src/Cargo.lock

@@ -99,7 +99,6 @@ dependencies = [
  "errno 0.2.8",
  "gag",
  "getset",
- "itertools",
  "libc",
  "log",
  "parse-display",
@@ -407,15 +406,6 @@ dependencies = [
  "windows-sys",
 ]
 
-[[package]]
-name = "itertools"
-version = "0.9.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "284f18f85651fe11e8a991b2adb42cb078325c996ed026d994719efcfca1d54b"
-dependencies = [
- "either",
-]
-
 [[package]]
 name = "lazy_static"
 version = "1.4.0"

rust-src/Cargo.toml

@@ -21,7 +21,6 @@ udev = "0.7.0"
 uuid = "1.2.2"
 gag = "1.0.0"
 getset = "0.1"
-itertools = "0.9"
 parse-display = "0.1"
 errno = "0.2"
 either = "1.5"

rust-src/src/cmd_mount.rs

@@ -76,12 +76,11 @@ fn parse_mount_options(options: impl AsRef<str>) -> (Option<String>, libc::c_ulo
             }
         });
 
-    use itertools::Itertools;
     (
         if opts.len() == 0 {
             None
         } else {
-            Some(opts.iter().join(","))
+            Some(opts.join(","))
         },
         flags,
     )