Merge pull request #49 from mlaz/mcumgr_fixes

Handle "UNKNOWN" on log_mgmt_impl_get_level
diff --git a/cmd/log_mgmt/port/mynewt/src/mynewt_log_mgmt.c b/cmd/log_mgmt/port/mynewt/src/mynewt_log_mgmt.c
index edff9a0..33dd774 100644
--- a/cmd/log_mgmt/port/mynewt/src/mynewt_log_mgmt.c
+++ b/cmd/log_mgmt/port/mynewt/src/mynewt_log_mgmt.c
@@ -132,8 +132,12 @@
 {
     const char *name;
 
+    if (idx >= LOG_LEVEL_MAX) {
+        return LOG_MGMT_ERR_ENOENT;
+    }
+
     name = LOG_LEVEL_STR(idx);
-    if (name == NULL) {
+    if (!strcmp(name, "UNKNOWN")) {
         return LOG_MGMT_ERR_ENOENT;
     } else {
         *out_level_name = name;