selftests:kvm: fix get_warnings_count() ignoring fscanf() return warn

[ Upstream commit 39a71f712d8a13728febd8f3cb3f6db7e1fa7221 ]

Fix get_warnings_count() to check fscanf() return value to get rid
of the following warning:

x86_64/mmio_warning_test.c: In function ‘get_warnings_count’:
x86_64/mmio_warning_test.c:85:2: warning: ignoring return value of ‘fscanf’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   85 |  fscanf(f, "%d", &warnings);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c b/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
index e6480fd..8039e1e 100644 (file)
--- a/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
+++ b/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
@@ -82,7 +82,8 @@ int get_warnings_count(void)
        FILE *f;
 
        f = popen("dmesg | grep \"WARNING:\" | wc -l", "r");
-       fscanf(f, "%d", &warnings);
+       if (fscanf(f, "%d", &warnings) < 1)
+               warnings = 0;
        fclose(f);
 
        return warnings;