nodemask: Drop duplicate check in for_each_node_mask()

The return value type is changed from 'int' to 'unsigned int' since
commit 0dfe540 ("nodemask: Fix return values to be unsigned").
Besides, the conversion between 'int' and 'unsigned int' on the
parameter @node is guaranteed to be safe due to the limited range of
MAX_NUMNODES and CONFIG_NODES_SHIFT. By the way, '(node >= 0)' should
have been '(node) >= 0' actually.

It's unnecessary to check if their return values are greater or equal
to 0 in for_each_node_mask(). Remove it.

No functional change intended.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

Author: Gavin Shan

include/linux/nodemask.h

@@ -385,7 +385,7 @@ static inline void __nodes_fold(nodemask_t *dstp, const nodemask_t *origp,
 #if MAX_NUMNODES > 1
 #define for_each_node_mask(node, mask)				    \
 	for ((node) = first_node(mask);				    \
-	     (node >= 0) && (node) < MAX_NUMNODES;		    \
+	     (node) < MAX_NUMNODES;				    \
 	     (node) = next_node((node), (mask)))
 #else /* MAX_NUMNODES == 1 */
 #define for_each_node_mask(node, mask)                                  \