fix doxgen fail

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/include/mbedtls/pk.h b/include/mbedtls/pk.h
index 45c80b4..345762c 100644
--- a/include/mbedtls/pk.h
+++ b/include/mbedtls/pk.h
@@ -568,7 +568,7 @@
  * \note            For RSA, md_alg may be MBEDTLS_MD_NONE if hash_len != 0.
  *                  For ECDSA, md_alg may never be MBEDTLS_MD_NONE.
  */
-int mbedtls_pk_sign_ext( mbedtls_pk_type_t type,
+int mbedtls_pk_sign_ext( mbedtls_pk_type_t pk_type,
                          mbedtls_pk_context *ctx,
                          mbedtls_md_type_t md_alg,
                          const unsigned char *hash, size_t hash_len,
diff --git a/library/pk.c b/library/pk.c
index 369472a..0dab428 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -522,7 +522,7 @@
 /*
  * Make a signature with options
  */
-int mbedtls_pk_sign_ext( mbedtls_pk_type_t type,
+int mbedtls_pk_sign_ext( mbedtls_pk_type_t pk_type,
                          mbedtls_pk_context *ctx,
                          mbedtls_md_type_t md_alg,
                          const unsigned char *hash, size_t hash_len,
@@ -536,10 +536,10 @@
     if( ctx->pk_info == NULL )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 
-    if( ! mbedtls_pk_can_do( ctx, type ) )
+    if( ! mbedtls_pk_can_do( ctx, pk_type ) )
         return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
 
-    if( type != MBEDTLS_PK_RSASSA_PSS )
+    if( pk_type != MBEDTLS_PK_RSASSA_PSS )
     {
         return( mbedtls_pk_sign( ctx, md_alg, hash, hash_len,
                                  sig, sig_size, sig_len, f_rng, p_rng ) );