rust: pin-init: call try_[pin_]init! from [pin_]init! instead of __init_internal!

The `[pin_]init!` macros have the same behavior as the `try_[pin_]init!`
macros, except that they set the error type to `Infallible`.
Instead of calling the primitive `__init_internal!` with the correct
parameters, the same can thus be achieved by calling `try_[pin_]init!`.
Since this makes it more clear what their behavior is, simplify the
implementations of `[pin_]init!`.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-7-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: BennoLossin

rust/pin-init/src/lib.rs

@@ -676,16 +676,9 @@ macro_rules! pin_init {
     ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
         $($fields:tt)*
     }) => {
-        $crate::__init_internal!(
-            @this($($this)?),
-            @typ($t $(::<$($generics),*>)?),
-            @fields($($fields)*),
-            @error(::core::convert::Infallible),
-            @data(PinData, use_data),
-            @has_data(HasPinData, __pin_data),
-            @construct_closure(pin_init_from_closure),
-            @munch_fields($($fields)*),
-        )
+        $crate::try_pin_init!($(&$this in)? $t $(::<$($generics),*>)? {
+            $($fields)*
+        }? ::core::convert::Infallible)
     };
 }
 
@@ -784,16 +777,9 @@ macro_rules! init {
     ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
         $($fields:tt)*
     }) => {
-        $crate::__init_internal!(
-            @this($($this)?),
-            @typ($t $(::<$($generics),*>)?),
-            @fields($($fields)*),
-            @error(::core::convert::Infallible),
-            @data(InitData, /*no use_data*/),
-            @has_data(HasInitData, __init_data),
-            @construct_closure(init_from_closure),
-            @munch_fields($($fields)*),
-        )
+        $crate::try_init!($(&$this in)? $t $(::<$($generics),*>)? {
+            $($fields)*
+        }? ::core::convert::Infallible)
     }
 }