net_sockets: Fix typo in net_would_block()

Fixes #528
diff --git a/library/net_sockets.c b/library/net_sockets.c
index 816b130..5d538bf 100644
--- a/library/net_sockets.c
+++ b/library/net_sockets.c
@@ -284,7 +284,7 @@
     int err = errno;
 
     /*
-     * Never return 'WOULD BLOCK' on a non-blocking socket
+     * Never return 'WOULD BLOCK' on a blocking socket
      */
     if( ( fcntl( ctx->fd, F_GETFL ) & O_NONBLOCK ) != O_NONBLOCK )
     {