fix getBpfSupportLevel() cache wrt. multi-threading

In case it happens to get called twice in parallel on
startup.  It's never a mistake to do extra calls to the
uncached version.

Test: build, atest
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I2605ed2ebc4ee331b2ca6c9fa915203d70415d7f
diff --git a/libbpf_android/BpfUtils.cpp b/libbpf_android/BpfUtils.cpp
index c175d98..535c537 100644
--- a/libbpf_android/BpfUtils.cpp
+++ b/libbpf_android/BpfUtils.cpp
@@ -136,14 +136,7 @@
 }
 
 BpfLevel getBpfSupportLevel() {
-    static bool initialized = false;
-    static BpfLevel cache;
-
-    if (!initialized) {
-        initialized = true;
-        cache = getUncachedBpfSupportLevel();
-    }
-
+    static BpfLevel cache = getUncachedBpfSupportLevel();
     return cache;
 }