Modified underflow error text to print overflow instead. End users are more familiar with handling overflow errors, even if underflow may be technically correct

Author: cmonr

rtos/TARGET_CORTEX/mbed_rtx_handlers.c

@@ -45,7 +45,8 @@ __NO_RETURN uint32_t osRtxErrorNotify (uint32_t code, void *object_id)
     switch (code) {
       case osRtxErrorStackUnderflow:
         // Stack underflow detected for thread (thread_id=object_id)
-        error("CMSIS-RTOS error: Stack underflow (status: 0x%X, task ID: 0x%X, task name: %s)\n\r",
+        // Note: "overflow" is printed instead of "underflow" due to end user familiarity with overflow errors
+        error("CMSIS-RTOS error: Stack overflow (status: 0x%X, task ID: 0x%X, task name: %s)\n\r",
                 code, object_id, osThreadGetName(object_id));
         break;
       case osRtxErrorISRQueueOverflow: