kfifo: fix kfifo_alloc() and kfifo_init()

Fix kfifo_alloc() and kfifo_init() to alloc at least the requested number
of elements.  Since the kfifo operates on power of 2 the request size will
be rounded up to the next power of two.
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lib/kfifo.c

@@ -42,8 +42,7 @@ int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
 	 * round down to the next power of 2, since our 'let the indices
 	 * wrap' technique works only in this case.
 	 */
-	if (!is_power_of_2(size))
-		size = rounddown_pow_of_two(size);
+	size = roundup_pow_of_two(size);
 
 	fifo->in = 0;
 	fifo->out = 0;
@@ -83,8 +82,7 @@ int __kfifo_init(struct __kfifo *fifo, void *buffer,
 {
 	size /= esize;
 
-	if (!is_power_of_2(size))
-		size = rounddown_pow_of_two(size);
+	size = roundup_pow_of_two(size);
 
 	fifo->in = 0;
 	fifo->out = 0;