net: fix cpu_max_bits_warn() usage in netif_attrmask_next{,_and}

The functions require to be passed with a cpu index prior to one that is
the first to start search, so the valid input range is [-1, nr_cpu_ids-1).
However, the code checks against [-1, nr_cpu_ids).
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

include/linux/netdevice.h

@@ -3643,9 +3643,8 @@ static inline bool netif_attr_test_online(unsigned long j,
 static inline unsigned int netif_attrmask_next(int n, const unsigned long *srcp,
 					       unsigned int nr_bits)
 {
-	/* -1 is a legal arg here. */
-	if (n != -1)
-		cpu_max_bits_warn(n, nr_bits);
+	/* n is a prior cpu */
+	cpu_max_bits_warn(n + 1, nr_bits);
 
 	if (srcp)
 		return find_next_bit(srcp, nr_bits, n + 1);
@@ -3666,9 +3665,8 @@ static inline int netif_attrmask_next_and(int n, const unsigned long *src1p,
 					  const unsigned long *src2p,
 					  unsigned int nr_bits)
 {
-	/* -1 is a legal arg here. */
-	if (n != -1)
-		cpu_max_bits_warn(n, nr_bits);
+	/* n is a prior cpu */
+	cpu_max_bits_warn(n + 1, nr_bits);
 
 	if (src1p && src2p)
 		return find_next_and_bit(src1p, src2p, nr_bits, n + 1);