Enable exporting the non-uapi scsi headers.

Callers are supposed to #include <scsi/sg.h> but if we tell soong to add
bionic/libc/kernel/android/ to the include path, the uapi headers in there
would be (unintentionally) accessible as either <linux/name.h> or
<uapi/linux/name.h>.

Bug: N/A (hit while upgrading strace to 4.17)
Test: builds
Change-Id: I8d47dd51da688c38f747a255d401dfb2c209c805
diff --git a/libc/Android.bp b/libc/Android.bp
index cda9eaa..5a1c287 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -2097,7 +2097,7 @@
 
 ndk_headers {
     name: "libc_kernel_android_scsi",
-    from: "kernel/android/scsi",
+    from: "kernel/android/scsi/scsi",
     to: "scsi",
     srcs: ["kernel/android/scsi/**/*.h"],
     license: "NOTICE",