Fix whitespace style

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/hkdf.c b/library/hkdf.c
index 379035d..3b9942c 100644
--- a/library/hkdf.c
+++ b/library/hkdf.c
@@ -115,7 +115,7 @@
 
     n = okm_len / hash_len;
 
-    if( (okm_len % hash_len) != 0 )
+    if( okm_len % hash_len != 0 )
     {
         n++;
     }
@@ -131,7 +131,7 @@
 
     mbedtls_md_init( &ctx );
 
-    if( (ret = mbedtls_md_setup( &ctx, md, 1) ) != 0 )
+    if( ( ret = mbedtls_md_setup( &ctx, md, 1 ) ) != 0 )
     {
         goto exit;
     }