Update bench-code for addressing CI problem

Unit test code is in test-xbzrle.c, and benchmark code is in xbzrle-bench.c
for performance benchmarking. we have modified xbzrle-bench.c to address
CI problem.

Signed-off-by: ling xu <ling1.xu@intel.com>
Co-authored-by: Zhou Zhao <zhou.zhao@intel.com>
Co-authored-by: Jun Jin <jun.i.jin@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
diff --git a/tests/bench/meson.build b/tests/bench/meson.build
index 279a8fc..7477a1f 100644
--- a/tests/bench/meson.build
+++ b/tests/bench/meson.build
@@ -3,6 +3,12 @@
                        sources: 'qht-bench.c',
                        dependencies: [qemuutil])
 
+if have_system
+xbzrle_bench = executable('xbzrle-bench',
+                       sources: 'xbzrle-bench.c',
+                       dependencies: [qemuutil,migration])
+endif
+
 executable('atomic_add-bench',
            sources: files('atomic_add-bench.c'),
            dependencies: [qemuutil],