msm: kgsl: fix sync file error handling

We need to call put_unused_fd() on failure, but only if
a file hasn't been stored into the fd yet. This function
wasn't called from kgsl_ioctl_syncsource_create_fence()
and was called incorrectly from kgsl_add_fence_event().
Reorder our sync_fence_install() calls to happen after
all possible failures so that error cleanup will be
correct.

Change-Id: I0e7bb459f2acc010446ac5e5b3b72c8b16cce079
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Signed-off-by: Kevin F. Haggerty <kevin.f.haggerty@gmail.com>
haggertk: Backport to 3.4

drivers/gpu/msm/kgsl_sync.c

@@ -159,12 +159,12 @@ int kgsl_add_fence_event(struct kgsl_device *device,
 		ret = -EINVAL;
 		goto fail_fd;
 	}
-	sync_fence_install(fence, priv.fence_fd);
 
 	if (copy_to_user(data, &priv, sizeof(priv))) {
 		ret = -EFAULT;
 		goto fail_copy_fd;
 	}
+	sync_fence_install(fence, priv.fence_fd);
 
 	/*
 	 * Hold the context ref-count for the event - it will get released in