style fix: (void)

src/core/ngx_log.c

diff --git a/src/core/ngx_log.c b/src/core/ngx_log.c
index 58e1b08..e82e32d 100644
--- a/src/core/ngx_log.c
+++ b/src/core/ngx_log.c
@@ -174,7 +174,7 @@
 
     (void) ngx_sprintf(msg, "[%V]: ", &err_levels[level]);
 
-    ngx_write_fd(ngx_stderr, msg, p - msg);
+    (void) ngx_write_fd(ngx_stderr, msg, p - msg);
 }
 
 
@@ -259,7 +259,7 @@
 
     ngx_linefeed(p);
 
-    ngx_write_fd(ngx_stderr, errstr, p - errstr);
+    (void) ngx_write_fd(ngx_stderr, errstr, p - errstr);
 }