NTB: Fix incorrect return check in ntb_perf

kthread_create_no_node() returns error pointers, never NULL. Fix check so
it handles error correctly.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
index cf19ff07680d..d82d10791e7d 100644
--- a/drivers/ntb/test/ntb_perf.c
+++ b/drivers/ntb/test/ntb_perf.c
@@ -615,9 +615,7 @@ static ssize_t debugfs_run_write(struct file *filp, const char __user *ubuf,
                                 kthread_create_on_node(ntb_perf_thread,
                                                        (void *)pctx,
                                                        node, "ntb_perf %d", i);
-                        if (pctx->thread)
-                                wake_up_process(pctx->thread);
-                        else {
+                        if (IS_ERR(pctx->thread)) {
                                 perf->run = false;
                                 for (i = 0; i < MAX_THREADS; i++) {
                                         if (pctx->thread) {
@@ -625,7 +623,8 @@ static ssize_t debugfs_run_write(struct file *filp, const char __user *ubuf,
                                                 pctx->thread = NULL;
                                         }
                                 }
-                        }
+                        } else
+                                wake_up_process(pctx->thread);
 
                         if (perf->run == false)
                                 return -ENXIO;