Avoid NPE if buffer contains a null am: 6276f53a12 am: f726d86389

Original change: https://android-review.googlesource.com/c/platform/tools/loganalysis/+/2020975

Change-Id: I9bb60fd5f87ec9d62a866828da107f4a61434f30
diff --git a/src/com/android/loganalysis/parser/LogcatParser.java b/src/com/android/loganalysis/parser/LogcatParser.java
index b32536d..366b851 100644
--- a/src/com/android/loganalysis/parser/LogcatParser.java
+++ b/src/com/android/loganalysis/parser/LogcatParser.java
@@ -192,6 +192,9 @@
     @Override
     public LogcatItem parse(List<String> lines) {
         for (String line : lines) {
+            if (line == null) {
+                continue;
+            }
             parseLine(line);
         }
         commit();