Enable -Werror on zipalign

And fix the last warning to enable this flag.

Bug: 27695718
Change-Id: I70eb9c87530a9b982fbe83abea706908f0ce0356

tools/zipalign/Android.mk

@@ -35,4 +35,6 @@ endif # BUILD_HOST_static
 LOCAL_MODULE := zipalign
 LOCAL_MODULE_HOST_OS := darwin linux windows
 
+LOCAL_CFLAGS := -Werror
+
 include $(BUILD_HOST_EXECUTABLE)

tools/zipalign/ZipEntry.cpp

@@ -142,7 +142,7 @@ void ZipEntry::initNew(const char* fileName, const char* comment)
  *
  * Initializes the CDE and the LFH.
  */
-status_t ZipEntry::initFromExternal(const ZipFile* pZipFile,
+status_t ZipEntry::initFromExternal(const ZipFile*,
     const ZipEntry* pEntry)
 {
     /*
@@ -694,4 +694,3 @@ void ZipEntry::CentralDirEntry::dump(void) const
     if (mFileComment != NULL)
         ALOGD("  comment: '%s'\n", mFileComment);
 }
-