pipe: remove redundant assignment to pointer buf

The pointer buf is being assigned a value that is never read, it is being re-assigned later on closer to where is it required to be set. The assignment is redundant and can be removed. Cleans up clang scan build warning:

fs/pipe.c:490:24: warning: Value stored to 'buf' during its initialization is never read [deadcode.DeadStores]

---
 fs/pipe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index cc28623a67b6..d19229df66ee 100644
@@ -487,7 +487,7 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from)
 		head = pipe->head;
 		if (!pipe_full(head, pipe->tail, pipe->max_usage)) {
 			unsigned int mask = pipe->ring_size - 1;
-			struct pipe_buffer *buf = &pipe->bufs[head & mask];
+			struct pipe_buffer *buf;
 			struct page *page = pipe->tmp_page;
 			int copied;
 

2.33.1