[RFC PATCH-for-5.1?] tests/tcg/multiarch/linux-test: Skip test if nanosleep missing (Travis)

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

The time test sometimes fails on Travis-CI [*]:

    TEST    linux-test on aarch64
  tests/tcg/multiarch/linux-test.c:237: nanosleep
  make[2]: *** [run-linux-test] Error 1
  make: *** [run-tcg-tests-aarch64-linux-user] Error 2

As this seems due to a container limitation on Travis-CI,
simply skip the test there.

[*] https://travis-ci.org/github/qemu/qemu/jobs/710005078#L3706

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
RFC because per Laurent Vivier we are not using the correct libc
    while cross-linking the test (maybe change in the container
    packages?)
---
 tests/tcg/multiarch/linux-test.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tests/tcg/multiarch/linux-test.c b/tests/tcg/multiarch/linux-test.c
index 8a7c15cd31..c7dfdec9ec 100644
--- a/tests/tcg/multiarch/linux-test.c
+++ b/tests/tcg/multiarch/linux-test.c
@@ -233,8 +233,13 @@ static void test_time(void)
     ts.tv_sec = 0;
     ts.tv_nsec = 20 * 1000000;
     chk_error(nanosleep(&ts, &rem));
-    if (rem.tv_sec != 1)
+    if (rem.tv_sec != 1) {
+        if (getenv("TRAVIS_ARCH")) {
+            printf("nanosleep missing? skipping 'time' test\n");
+            return;
+        }
         error("nanosleep");
+    }
     chk_error(gettimeofday(&tv2, NULL));
     ti = tv2.tv_sec - tv.tv_sec;
     if (ti >= 2)
-- 
2.21.3