Fixed wpi_setErrnoError to print the error name

Previously, wpi_setErrnoError and wpi_setErrnoErrorWithContext
always printed "Unknown errno" whenever a C library error
occured.

Change-Id: Ib235138eea0e83b0d7462dfd6e834e3499e3b0c5

hal/include/HAL/cpp/StackTrace.hpp

@@ -9,5 +9,4 @@
 extern "C"
 {
 	void printCurrentStackTrace();
-	bool getErrnoToName(int32_t errNo, char* name);
 }