Fix incorrect relocations for x86.

These calls were not going through the PLT like they should have been.

Bug: 16853291
Change-Id: Id70488b077256a70137c4417f21be2c2d1d4341c
diff --git a/libc/arch-x86/bionic/syscall.S b/libc/arch-x86/bionic/syscall.S
index 8e76c4e..2139100 100644
--- a/libc/arch-x86/bionic/syscall.S
+++ b/libc/arch-x86/bionic/syscall.S
@@ -38,7 +38,7 @@
     # Yes, so set errno.
     negl    %eax
     pushl   %eax
-    call    __set_errno
+    call    PIC_PLT(__set_errno)
     addl    $4, %esp
 1:
     # Restore the callee save registers.