crypto: pkcs1pad - comply with crypto_akcipher_maxsize()

crypto_akcipher_maxsize() asks for the output buffer size without
caring for errors. It allways assume that will be called after
a valid setkey. Comply with it and return what he wants.

crypto_akcipher_maxsize() now returns an unsigned int.
Remove the unnecessary check.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/rsa-pkcs1pad.c

@@ -120,9 +120,6 @@ static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
 
 	/* Find out new modulus size from rsa implementation */
 	err = crypto_akcipher_maxsize(ctx->child);
-	if (err < 0)
-		return err;
-
 	if (err > PAGE_SIZE)
 		return -ENOTSUPP;
 
@@ -144,9 +141,6 @@ static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
 
 	/* Find out new modulus size from rsa implementation */
 	err = crypto_akcipher_maxsize(ctx->child);
-	if (err < 0)
-		return err;
-
 	if (err > PAGE_SIZE)
 		return -ENOTSUPP;
 
@@ -154,7 +148,7 @@ static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
 	return 0;
 }
 
-static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
+static unsigned int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
 {
 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 
@@ -164,7 +158,7 @@ static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
 	 * decrypt/verify.
 	 */
 
-	return ctx->key_size ?: -EINVAL;
+	return ctx->key_size;
 }
 
 static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,