bitops: use the same mechanism for get_count_order[_long]

These two functions share the same logic.
Signed-off-by: NWei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lkml.kernel.org/r/20200807085837.11697-3-richard.weiyang@linux.alibaba.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/bitops.h

@@ -188,12 +188,10 @@ static inline unsigned fls_long(unsigned long l)
 
 static inline int get_count_order(unsigned int count)
 {
-	int order;
+	if (count == 0)
+		return -1;
 
-	order = fls(count) - 1;
-	if (count & (count - 1))
-		order++;
-	return order;
+	return fls(--count);
 }
 
 /**