remove unnecessary check.

This removes the check that always evaluates to 'true'.
the salient point here is that debug_buf is an array, not a pointer:

include/libevdev/libevdev_event.h:
struct input_event debug_buf[DEBUG_BUF_SIZE];

BUG=chromium:450371
TEST=It compiles with new clang.

Change-Id: I3867f4cfbc30e26a0f51a8f05a402f12463d8713
Reviewed-on: https://chromium-review.googlesource.com/242045
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Yunlian Jiang <yunlian@chromium.org>
Commit-Queue: Yunlian Jiang <yunlian@chromium.org>
diff --git a/src/libevdev.c b/src/libevdev.c
index a7d3438..589cb28 100644
--- a/src/libevdev.c
+++ b/src/libevdev.c
@@ -65,12 +65,10 @@
 
     /* Read as many whole struct input_event objects as we can into the
        circular buffer */
-    if (evstate->debug_buf) {
-      for (i = 0; i < len / sizeof(*ev); i++) {
-        evstate->debug_buf[evstate->debug_buf_tail] = ev[i];
-        evstate->debug_buf_tail =
-            (evstate->debug_buf_tail + 1) % DEBUG_BUF_SIZE;
-      }
+    for (i = 0; i < len / sizeof(*ev); i++) {
+      evstate->debug_buf[evstate->debug_buf_tail] = ev[i];
+      evstate->debug_buf_tail =
+          (evstate->debug_buf_tail + 1) % DEBUG_BUF_SIZE;
     }
 
     /* kernel always delivers complete events, so len must be sizeof *ev */