um: Add missing NR_CPUS include
We need linux/threads.h for that variable.
Fixes: 8bba077066d6d0 ("um: Set number of CPUs")
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 92f7ee1..03b3c4c 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -21,6 +21,7 @@
#include <registers.h>
#include <skas.h>
#include <sysdep/stub.h>
+#include <linux/threads.h>
int is_skas_winch(int pid, int fd, void *data)
{
