Silent failing TestWatchpointCount.py aarch64/linux

Skip TestWatchpointCount.py for aarch64-linux to fix lldb aarch64 linux buildbot.

http://lab.llvm.org:8011/builders/lldb-aarch64-ubuntu/

lldb/test/API/commands/watchpoints/watchpoint_count/TestWatchpointCount.py

@@ -10,6 +10,7 @@ class TestWatchpointCount(TestBase):
     def setUp(self):
         TestBase.setUp(self)
 
+    @skipIf(oslist=["linux"], archs=["aarch64"])
     def test_watchpoint_count(self):
         self.build()
         (_, process, thread, _) = lldbutil.run_to_source_breakpoint(self, "patatino", lldb.SBFileSpec("main.c"))