Updated to v4.4.1 kernel headers.

Small modifications needed to allow compilation with the new headers:

- Manually modify bionic/libc/kernel/uapi/asm-mips/asm/siginfo.h to
  remove the uapi from the include.
- PR_XXX defines are now available for mips, so remove the definition
  from linker_mips.cpp.

Bug: 23789423
Change-Id: I6dc8a03b012426d3a937db15cb24d3a50fab5a8c
diff --git a/libc/kernel/uapi/linux/nbd.h b/libc/kernel/uapi/linux/nbd.h
index 588fbd8..e24920b 100644
--- a/libc/kernel/uapi/linux/nbd.h
+++ b/libc/kernel/uapi/linux/nbd.h
@@ -47,23 +47,22 @@
 #define NBD_FLAG_SEND_FLUSH (1 << 2)
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define NBD_FLAG_SEND_TRIM (1 << 5)
-#define nbd_cmd(req) ((req)->cmd[0])
 #define NBD_REQUEST_MAGIC 0x25609513
 #define NBD_REPLY_MAGIC 0x67446698
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 struct nbd_request {
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
   __be32 magic;
   __be32 type;
   char handle[8];
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
   __be64 from;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
   __be32 len;
 } __attribute__((packed));
 struct nbd_reply {
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
   __be32 magic;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
   __be32 error;
   char handle[8];
 };
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */