ptest-runner: Bump to 2.4.4 (95f528c)

Changes in 2.4.4:
95f528c utils.c: run_ptests improve error handling on ptests iteration
c48e5fc utils.c: run-ptests improve pseudo-terminal handling

Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>