fixing typos

Author: Niveditha Ramasubramanian

DataFormats/Detectors/ITSMFT/common/include/DataFormatsITSMFT/NoiseMap.h

@@ -204,7 +204,7 @@ class NoiseMap
 
   NoiseMap merge(NoiseMap* prev){
     int incre=0;
-    for (size_t i = 0; i < 920; ++i) { //920 is the total number of chips in MFT
+    for (size_t i = 0; i < (int)mNoisyPixels.size(); ++i) { //920 is the total number of chips in MFT
       for (const auto& prev_np : prev->mNoisyPixels[i]) { //only enters this for loop if the "i" chip exists. 
 	bool existsInCurrentMap = false;
 	for (const auto& current_np : mNoisyPixels[i]) {