Remove executable bit from Makefiles and C source.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
syscalls/mount03: Convert to tst_acquire_device()

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
syscalls/mount06: Convert to tst_acquire_device()

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>