Merge branch 'setns'

* setns:
  ns: Wire up the setns system call

Done as a merge to make it easier to fix up conflicts in arm due to
addition of sendmmsg system call
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index 3de689a..2c04ed5 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -401,6 +401,7 @@
 #define __NR_clock_adjtime		(__NR_SYSCALL_BASE+372)
 #define __NR_syncfs			(__NR_SYSCALL_BASE+373)
 #define __NR_sendmmsg			(__NR_SYSCALL_BASE+374)
+#define __NR_setns			(__NR_SYSCALL_BASE+375)
 
 /*
  * The following SWIs are ARM private.