Remove the useless _C_LABEL from generated system calls.

Change-Id: Id1d2fd39972652831ea825f6f9cf940b08f42b5c
diff --git a/libc/tools/gensyscalls.py b/libc/tools/gensyscalls.py
index da30da2..8a5f3d2 100755
--- a/libc/tools/gensyscalls.py
+++ b/libc/tools/gensyscalls.py
@@ -288,7 +288,7 @@
 
     # Use hidden visibility for any functions beginning with underscores.
     if pointer_length == 64 and syscall["func"].startswith("__"):
-        stub += '.hidden _C_LABEL(' + syscall["func"] + ')\n'
+        stub += '.hidden ' + syscall["func"] + '\n'
 
     return stub