rust: alloc: update VecExt to take allocation flags

We also rename the methods by removing the `try_` prefix since the names
are available due to our usage of the `no_global_oom_handling` config
when building the `alloc` crate.

Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240328013603.206764-8-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust/kernel/error.rs

@@ -6,10 +6,7 @@
 
 use crate::str::CStr;
 
-use alloc::{
-    alloc::{AllocError, LayoutError},
-    collections::TryReserveError,
-};
+use alloc::alloc::{AllocError, LayoutError};
 
 use core::convert::From;
 use core::fmt;
@@ -192,12 +189,6 @@ impl From<Utf8Error> for Error {
     }
 }
 
-impl From<TryReserveError> for Error {
-    fn from(_: TryReserveError) -> Error {
-        code::ENOMEM
-    }
-}
-
 impl From<LayoutError> for Error {
     fn from(_: LayoutError) -> Error {
         code::ENOMEM