[PATCH V2] no need for checking it

["Figo.zhang" <figo1802@gmail.com>]

vfree() does it's own NULL checking,so no need for check before
calling it.

'pages' is local variable argment,so in v2, it is no need assignment
 to NULL.

Signed-off-by: Figo.zhang <figo1802@gmail.com>
---   
drivers/staging/comedi/drivers.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index 6e13e45..587283a 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -495,9 +495,8 @@ int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
 				vmap(pages, n_pages, VM_MAP,
 				PAGE_KERNEL_NOCACHE);
 		}
-		if (pages) {
-			vfree(pages);
-		}
+		vfree(pages);
+		
 		if (async->prealloc_buf == NULL) {
 			/* Some allocation failed above. */
 			if (async->buf_page_list) {