[lldb][test] Fix typo in decorator

(cherry picked from commit 61d569f)

Author: DavidSpickett

lldb/test/API/tools/lldb-dap/memory/TestDAP_memory.py

@@ -127,7 +127,7 @@ def test_readMemory(self):
         self.continue_to_exit()
 
     # Flakey on 32-bit Arm Linux.
-    @skipif(oslist=["linux"], archs=["arm$"])
+    @skipIf(oslist=["linux"], archs=["arm$"])
     def test_writeMemory(self):
         """
         Tests the 'writeMemory' request