Eliminate fOwnedNodes from symbol tables.

Now that DSLFP is gone, no one uses this. Previously, this was used to
stash the `sk_SampleCoord` Variable symbol:
https://skia-review.googlesource.com/c/skia/+/540301/1/src/sksl/dsl/DSLVar.cpp#b148

Change-Id: I4015dd7b29da004cd308fb21570a23014a2c66d2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/540303
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
1 file changed