[PATCH] tests/xs: Check asprintf result

[Jason Andryuk <jandryuk@xxxxxxxxx>]

Compiling xs-test.c on Ubuntu 21.04 fails with:

xs-test.c: In function ‘main’:
xs-test.c:486:5: error: ignoring return value of ‘asprintf’ declared with 
attribute ‘warn_unused_result’ [-Werror=unused-result]
  486 |     asprintf(&path, "%s/%u", TEST_PATH, getpid());
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Check the asprintf return and exit if it failed.

Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
---
Using exit(2) since it is used for the xs_open failure.
---
 tools/tests/xenstore/xs-test.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/tools/tests/xenstore/xs-test.c b/tools/tests/xenstore/xs-test.c
index c4c99c0661..f42c1cfe66 100644
--- a/tools/tests/xenstore/xs-test.c
+++ b/tools/tests/xenstore/xs-test.c
@@ -483,11 +483,20 @@ int main(int argc, char *argv[])
         return 0;
     }
 
-    asprintf(&path, "%s/%u", TEST_PATH, getpid());
+    ret = asprintf(&path, "%s/%u", TEST_PATH, getpid());
+    if (ret == -1) {
+        perror("asprintf");
+        exit(2);
+    }
+
     for ( t = 0; t < WRITE_BUFFERS_N; t++ )
     {
         memset(write_buffers[t], 'a' + t, WRITE_BUFFERS_SIZE);
-        asprintf(&paths[t], "%s/%c", path, 'a' + t);
+        ret = asprintf(&paths[t], "%s/%c", path, 'a' + t);
+        if (ret == -1) {
+            perror("asprintf");
+            exit(2);
+        }
     }
 
     xsh = xs_open(0);
-- 
2.30.2