open_posix_testsuite/.../sigset/{6, 7}-1.c: fix error handling

int may not be large enough to hold return value from sigset():
  typedef void (*sighandler_t)(int);
  sighandler_t sigset(int sig, sighandler_t disp);

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Reviewed-by: Garrett Cooper <yanegomi@gmail.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
2 files changed