numa: make "nr_online_nodes" unsigned int

Number of online NUMA nodes can't be negative as well.  This doesn't
save space as the variable is used only in 32-bit context, but do it
anyway for consistency.

Link: http://lkml.kernel.org/r/20190201223151.GB15820@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 962c5e7..27e7fa3 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -445,7 +445,7 @@
 }
 
 extern unsigned int nr_node_ids;
-extern int nr_online_nodes;
+extern unsigned int nr_online_nodes;
 
 static inline void node_set_online(int nid)
 {
@@ -486,7 +486,7 @@
 #define first_memory_node	0
 #define next_online_node(nid)	(MAX_NUMNODES)
 #define nr_node_ids		1U
-#define nr_online_nodes		1
+#define nr_online_nodes		1U
 
 #define node_set_online(node)	   node_set_state((node), N_ONLINE)
 #define node_set_offline(node)	   node_clear_state((node), N_ONLINE)