free() strduped spi_path on quit.
Found by valgrind.
Change-Id: Iaa59c7258c920b5e60d615df790dfe815831b925
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Fixes: 83e0293f7b ("Add Linux SPI device SWD adapter support")
Reviewed-on: https://review.openocd.org/c/openocd/+/8732
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Richard Pasek <rpasek@google.com>