call drv_gem_bo_destroy from i915_bo_import

... when returning on error to close open gem handles.

BUG=chromium:738113
TEST=graphicsSanity on cyan

Change-Id: I19e30abc57349655b1f1c28d38aee67a39482cc6
Reviewed-on: https://chromium-review.googlesource.com/556402
Commit-Ready: Joe Kniss <djmk@google.com>
Tested-by: Joe Kniss <djmk@google.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
diff --git a/i915.c b/i915.c
index 59995b2..37a96fe 100644
--- a/i915.c
+++ b/i915.c
@@ -349,6 +349,7 @@
 
 	ret = drmIoctl(bo->drv->fd, DRM_IOCTL_I915_GEM_GET_TILING, &gem_get_tiling);
 	if (ret) {
+		drv_gem_bo_destroy(bo);
 		fprintf(stderr, "drv: DRM_IOCTL_I915_GEM_GET_TILING failed.");
 		return ret;
 	}