rust: io: avoid mentioning private fields in IoMem

Removed reference to internal variables in the comment of `IoMem`
This avoids using private variable names in public documentation.

Suggested-by: Miguel Ojeda <[email protected]>
Link: #1167
Signed-off-by: Sai Vishnu M <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Reworded title and adjusted tags. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

Author: saivishnu725

rust/kernel/io.rs

@@ -43,7 +43,7 @@ impl<const SIZE: usize> IoRaw<SIZE> {
     }
 }
 
-/// IO-mapped memory, starting at the base address @addr and spanning @maxlen bytes.
+/// IO-mapped memory region.
 ///
 /// The creator (usually a subsystem / bus such as PCI) is responsible for creating the
 /// mapping, performing an additional region request etc.