Update SX127x.cpp

src/modules/SX127x/SX127x.cpp

@@ -542,7 +542,7 @@ bool SX127x::fifoGet(volatile uint8_t* data, int totalLen, volatile int* rcvLen)
 
   // get the data
   this->mod->SPIreadRegisterBurst(RADIOLIB_SX127X_REG_FIFO, len, dataPtr);
-  (*rcvLen) += (len);
+  *rcvLen = *rcvLen + len;
 
   // check if we're done
   if(*rcvLen >= totalLen) {