cpumask: use find_first_and_bit()

cpumask_first_and() is an alias to cpumask_next_and(). Now we
efficient implementation for find_first_and_bit(), so switch
cpumask_first_and() to use it.

Signed-off-by: Yury Norov <yury.norov@gmail.com>

include/linux/cpumask.h

@@ -123,6 +123,12 @@ static inline unsigned int cpumask_first(const struct cpumask *srcp)
 	return 0;
 }
 
+static inline unsigned int cpumask_first_and(const struct cpumask *srcp1,
+					     const struct cpumask *srcp2)
+{
+	return 0;
+}
+
 static inline unsigned int cpumask_last(const struct cpumask *srcp)
 {
 	return 0;
@@ -592,7 +598,11 @@ static inline void cpumask_copy(struct cpumask *dstp,
  *
  * Returns >= nr_cpu_ids if no cpus set in both.  See also cpumask_next_and().
  */
-#define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
+static inline
+unsigned int cpumask_first_and(const struct cpumask *srcp1, const struct cpumask *srcp2)
+{
+	return find_first_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits);
+}
 
 /**
  * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2