Improve build_android_caselist error reporting.

Change-Id: I7f4b66ce23e5e9756d063a3eb62d0652cf7911ee
diff --git a/scripts/build_android_mustpass.py b/scripts/build_android_mustpass.py
index 5e7603d..8f987f7 100644
--- a/scripts/build_android_mustpass.py
+++ b/scripts/build_android_mustpass.py
@@ -137,7 +137,7 @@
 				ptrns.append(line)
 	return ptrns
 
-def applyPatterns (caseList, patterns, op):
+def applyPatterns (caseList, patterns, filename, op):
 	matched			= set()
 	errors			= []
 	curList			= copy(caseList)
@@ -173,15 +173,15 @@
 		print "ERROR: %s: %s" % (reason, pattern)
 
 	if len(errors) > 0:
-		die("Found %s invalid patterns" % len(errors))
+		die("Found %s invalid patterns while processing file %s" % (len(errors), filename))
 
 	return [c for c in caseList if op(c in matched)]
 
-def applyInclude (caseList, patterns):
-	return applyPatterns(caseList, patterns, lambda b: b)
+def applyInclude (caseList, patterns, filename):
+	return applyPatterns(caseList, patterns, filename, lambda b: b)
 
-def applyExclude (caseList, patterns):
-	return applyPatterns(caseList, patterns, lambda b: not b)
+def applyExclude (caseList, patterns, filename):
+	return applyPatterns(caseList, patterns, filename, lambda b: not b)
 
 def readPatternLists (mustpass):
 	lists = {}
@@ -197,10 +197,10 @@
 	for filter in filters:
 		ptrnList = patternLists[filter.filename]
 		if filter.type == Filter.TYPE_INCLUDE:
-			res = applyInclude(res, ptrnList)
+			res = applyInclude(res, ptrnList, filter.filename)
 		else:
 			assert filter.type == Filter.TYPE_EXCLUDE
-			res = applyExclude(res, ptrnList)
+			res = applyExclude(res, ptrnList, filter.filename)
 	return res
 
 def appendToHierarchy (root, casePath):