crypto: lskcipher - propagate errors from unaligned crypt

The while loop declares a second err variable that shadows the outer
one. When the crypt callback fails, the goto out path returns the outer
err, which still holds the -ENOMEM value assigned before the successful
allocation check. The real error from the cipher is discarded and the
caller sees -ENOMEM instead.

Drop the inner declaration so the callback error reaches the caller.

Verified with a test module that registers an lskcipher whose encrypt
callback fails with -EIO and calls it through a misaligned buffer.
An unpatched kernel returns -ENOMEM, a patched kernel returns -EIO.

Found with Clang's -Wshadow.

Fixes: 31865c4c4d ("crypto: skcipher - Add lskcipher")
Assisted-by: Claude:claude-fable-5
Signed-off-by: Karl Mehltretter <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

crypto/lskcipher.c

@@ -95,7 +95,6 @@ static int crypto_lskcipher_crypt_unaligned(
 
 	while (len >= bs) {
 		unsigned chunk = min((unsigned)PAGE_SIZE, len);
-		int err;
 
 		if (chunk > cs)
 			chunk &= ~(cs - 1);