bpfloader - minor fixups asked for by reviewer

As requested by Bernie on previous commit.

Bug: 190519702
Test: atest, TreeHugger - existing bpf programs load
  examination of bpfloader logs
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I4f5181f371d31dcf52768217ffd2b1b5b772103d
diff --git a/libbpf_android/Loader.cpp b/libbpf_android/Loader.cpp
index c10988d..b1af34f 100644
--- a/libbpf_android/Loader.cpp
+++ b/libbpf_android/Loader.cpp
@@ -514,14 +514,14 @@
         if (BPFLOADER_VERSION < md[i].bpfloader_min_ver) {
             ALOGI("skipping map %s which requires bpfloader min ver 0x%05x\n", mapNames[i].c_str(),
                   md[i].bpfloader_min_ver);
-            mapFds.push_back(std::move(fd));  // -1
+            mapFds.push_back(unique_fd());
             continue;
         }
 
         if (BPFLOADER_VERSION >= md[i].bpfloader_max_ver) {
             ALOGI("skipping map %s which requires bpfloader max ver 0x%05x\n", mapNames[i].c_str(),
                   md[i].bpfloader_max_ver);
-            mapFds.push_back(std::move(fd));  // -1
+            mapFds.push_back(unique_fd());
             continue;
         }
 
diff --git a/progs/include/bpf_map_def.h b/progs/include/bpf_map_def.h
index d80bfe7..b4fdd54 100644
--- a/progs/include/bpf_map_def.h
+++ b/progs/include/bpf_map_def.h
@@ -48,8 +48,8 @@
 #endif
 
 // These are the values used if these fields are missing
-#define DEFAULT_BPFLOADER_MIN_VER 0u        // v0.0
-#define DEFAULT_BPFLOADER_MAX_VER 0x10000u  // v1.0
+#define DEFAULT_BPFLOADER_MIN_VER 0u        // v0.0 (this is inclusive ie. >= v0.0)
+#define DEFAULT_BPFLOADER_MAX_VER 0x10000u  // v1.0 (this is exclusive ie. < v1.0)
 #define DEFAULT_SIZEOF_BPF_MAP_DEF 32       // v0.0 struct: enum + alignment padding + 7 uint
 #define DEFAULT_SIZEOF_BPF_PROG_DEF 20      // v0.0 struct: 4 uint + bool + alignment padding