Remove the useless _C_LABEL from generated system calls.

Change-Id: Id1d2fd39972652831ea825f6f9cf940b08f42b5c
diff --git a/libc/arch-mips64/syscalls/__timer_delete.S b/libc/arch-mips64/syscalls/__timer_delete.S
index c61b34c..8bbbdb7 100644
--- a/libc/arch-mips64/syscalls/__timer_delete.S
+++ b/libc/arch-mips64/syscalls/__timer_delete.S
@@ -23,4 +23,4 @@
     move ra, t0
     .set pop
 END(__timer_delete)
-.hidden _C_LABEL(__timer_delete)
+.hidden __timer_delete