Use Format_isValid() and Format_isEqual() instead of direct comparison

Change-Id: Ie87607aa514976947540a77775e6425c4e56e7d9
diff --git a/media/libnbaio/NBAIO.cpp b/media/libnbaio/NBAIO.cpp
index cc12671..18e0252 100644
--- a/media/libnbaio/NBAIO.cpp
+++ b/media/libnbaio/NBAIO.cpp
@@ -55,7 +55,7 @@
 
 unsigned Format_sampleRate(const NBAIO_Format& format)
 {
-    if (format == Format_Invalid) {
+    if (!Format_isValid(format)) {
         return 0;
     }
     switch (format & Format_SR_Mask) {
@@ -82,7 +82,7 @@
 
 unsigned Format_channelCount(const NBAIO_Format& format)
 {
-    if (format == Format_Invalid) {
+    if (!Format_isValid(format)) {
         return 0;
     }
     switch (format & Format_C_Mask) {
@@ -218,9 +218,9 @@
 {
     ALOGV("negotiate offers=%p numOffers=%u countersOffers=%p numCounterOffers=%u",
             offers, numOffers, counterOffers, numCounterOffers);
-    if (mFormat != Format_Invalid) {
+    if (Format_isValid(mFormat)) {
         for (size_t i = 0; i < numOffers; ++i) {
-            if (offers[i] == mFormat) {
+            if (Format_isEqual(offers[i], mFormat)) {
                 mNegotiated = true;
                 return i;
             }