Return with an explicit error code/message if sysfs isn't mounted.

git-svn-id: http://lm-sensors.org/svn/lm-sensors/branches/lm-sensors-3.0.0@4464 7894878c-1315-0410-8ee3-d5d059ff63e0

lib/error.c

@@ -34,7 +34,7 @@ static const char *errorlist[] =
    /* SENSORS_ERR_WILDCARDS */ "Wildcard found in chip name",
    /* SENSORS_ERR_NO_ENTRY  */ "No such feature known",
    /* SENSORS_ERR_ACCESS    */ "Can't read or write",
-   /* SENSORS_ERR_PROC      */ "Can't access procfs/sysfs file",
+   /* SENSORS_ERR_PROC      */ "Can't access sysfs file",
    /* SENSORS_ERR_DIV_ZERO  */ "Divide by zero",
    /* SENSORS_ERR_CHIP_NAME */ "Can't parse chip name",
    /* SENSORS_ERR_BUS_NAME  */ "Can't parse bus name",