igt/gem_exec_nop: Fix logical inversion for checking of valid execbuf

Only if the trial __gem_execbuf reports an error do we want to remove
the fancy LUT flags.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/tests/gem_exec_nop.c b/tests/gem_exec_nop.c
index 189f749..c82895b 100644
--- a/tests/gem_exec_nop.c
+++ b/tests/gem_exec_nop.c
@@ -72,7 +72,7 @@
 	execbuf.flags = ring_id;
 	execbuf.flags |= LOCAL_I915_EXEC_HANDLE_LUT;
 	execbuf.flags |= LOCAL_I915_EXEC_NO_RELOC;
-	if (__gem_execbuf(fd, &execbuf) == 0) {
+	if (__gem_execbuf(fd, &execbuf)) {
 		execbuf.flags = ring_id;
 		gem_execbuf(fd, &execbuf);
 	}
@@ -127,7 +127,7 @@
 	execbuf.buffer_count = 1;
 	execbuf.flags |= LOCAL_I915_EXEC_HANDLE_LUT;
 	execbuf.flags |= LOCAL_I915_EXEC_NO_RELOC;
-	if (__gem_execbuf(fd, &execbuf) == 0) {
+	if (__gem_execbuf(fd, &execbuf)) {
 		execbuf.flags = 0;
 		gem_execbuf(fd, &execbuf);
 	}