Remove the common bionic libc kernel directory.

The kernel include directory bionic/libc/kernel/common has been deleted,
so remove it from the include path.

Bug: 30072483
Change-Id: I71297f7ac1a9a28267b2aab270644abab2a085ae
diff --git a/cc/toolchain.go b/cc/toolchain.go
index 89485f8..0cb7c9c 100644
--- a/cc/toolchain.go
+++ b/cc/toolchain.go
@@ -146,8 +146,7 @@
 		"-isystem bionic/libc/arch-" + bionicArch + "/include",
 		"-isystem bionic/libc/include",
 		"-isystem bionic/libc/kernel/uapi",
-		"-isystem bionic/libc/kernel/android/uapi",
-		"-isystem bionic/libc/kernel/common",
 		"-isystem bionic/libc/kernel/uapi/asm-" + kernelArch,
+		"-isystem bionic/libc/kernel/android/uapi",
 	}, " ")
 }