egl: use _eglError's 'msg' as an actual message in EGL_KHR_debug

Seemingly, the original intent behind _eglError's 'msg' was aimed to
provide a function name.

At some point, people started using it the way EGL_KHR_debug's
callback() message is meant to be used. Aka providing meaningful
information to the developer/user.

Swap the funcName/msg argument order in the _eglDebugReport() call.
The 'funcName' variable is implicitly set, props to the
_eglSetFuncName() call at the start of each public entrypoint.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>

src/egl/main/eglcurrent.c

@@ -287,7 +287,7 @@ _eglError(EGLint errCode, const char *msg)
          type = EGL_DEBUG_MSG_ERROR_KHR;
       }
 
-      _eglDebugReport(errCode, msg, type, NULL);
+      _eglDebugReport(errCode, NULL, type, msg);
    } else
       _eglInternalError(errCode, msg);