net: 9p: Correct function names in the kerneldoc comments

Fix the following W=1 kernel build warning(s):

 net/9p/client.c:133: warning: expecting prototype for parse_options(). Prototype was for parse_opts() instead
 net/9p/client.c:269: warning: expecting prototype for p9_req_alloc(). Prototype was for p9_tag_alloc() instead
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/9p/client.c

@@ -122,7 +122,7 @@ static int get_protocol_version(char *s)
 }
 
 /**
- * parse_options - parse mount options into client structure
+ * parse_opts - parse mount options into client structure
  * @opts: options string passed from mount
  * @clnt: existing v9fs client information
  *
@@ -256,7 +256,7 @@ EXPORT_SYMBOL(p9_fcall_fini);
 static struct kmem_cache *p9_req_cache;
 
 /**
- * p9_req_alloc - Allocate a new request.
+ * p9_tag_alloc - Allocate a new request.
  * @c: Client session.
  * @type: Transaction type.
  * @max_size: Maximum packet size for this request.