Fix typo in SPIFFS and FFAT examples (#3322)

* fix typo in SPIFFS example

* fix typo in FFAT example

libraries/FFat/examples/FFat_Test/FFat_Test.ino

@@ -65,7 +65,7 @@ void writeFile(fs::FS &fs, const char * path, const char * message){
     if(file.print(message)){
         Serial.println("- file written");
     } else {
-        Serial.println("- frite failed");
+        Serial.println("- write failed");
     }
 }
 

libraries/SPIFFS/examples/SPIFFS_Test/SPIFFS_Test.ino

@@ -63,7 +63,7 @@ void writeFile(fs::FS &fs, const char * path, const char * message){
     if(file.print(message)){
         Serial.println("- file written");
     } else {
-        Serial.println("- frite failed");
+        Serial.println("- write failed");
     }
 }