fix races in dashcircle.cpp

Remove static from locals that are not constexpr.

See
https://task-driver.skia.org/logs/sMqS6sn7QDHLAJjHkSg7/65e8489b-9f04-4da5-bea4-d996dc0bb9ba

Change-Id: I2c1d75c8cd2866b500b0d33ac8a1b8cd9b9fb567
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/377940
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
1 file changed