Assume that /proc/meminfo can be missing

Travis tests are failing, probably because /proc/meminfo is not available
in the test environment. The same might be true in some virtualized systems,
so just treat missing /proc/meminfo as a sign that hibernation is not
possible.

src/test/test-fileio.c

@@ -232,12 +232,16 @@ static void test_executable_is_script(void) {
 static void test_status_field(void) {
         _cleanup_free_ char *t = NULL, *p = NULL, *s = NULL;
         unsigned long long total, buffers;
+        int r;
 
         assert_se(get_status_field("/proc/self/status", "\nThreads:", &t) == 0);
         puts(t);
         assert_se(streq(t, "1"));
 
-        assert_se(get_status_field("/proc/meminfo", "MemTotal:", &p) == 0);
+        r = get_status_field("/proc/meminfo", "MemTotal:", &p);
+        if (r == -ENOENT)
+                return;
+        assert(r == 0);
         puts(p);
         assert_se(safe_atollu(p, &total) == 0);