tests/linux: add max_vcores()

Signed-off-by: Barret Rhoden <brho@cs.berkeley.edu>
diff --git a/tests/linux/misc-compat.h b/tests/linux/misc-compat.h
index e6832e4..bf9a04b 100644
--- a/tests/linux/misc-compat.h
+++ b/tests/linux/misc-compat.h
@@ -34,8 +34,11 @@
 
 #define vcore_id() (-1)
 
+/* This isn't num_vcores, but it's all Linux has */
 #define num_vcores() ((int)sysconf(_SC_NPROCESSORS_ONLN))
 
+#define max_vcores() ((int)sysconf(_SC_NPROCESSORS_ONLN))
+
 #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
 
 typedef void* atomic_t;