Logged a busy-device fstab-removal failure at ERR, not INFO

VerifyNotInFstab logged the "device busy, cannot remove from fstab"
interruption at INFO. An INTERRUPTED outcome should surface at ERR so it
is visible without verbose logging. Split out from the CFE-90 work as an
unrelated log-level correction.

Author: nickanderson

cf-agent/nfs.c

@@ -851,7 +851,7 @@ int VerifyNotInFstab(EvalContext *ctx, char *name, const Attributes *a, const Pr
 
                 if (strstr(line, "busy"))
                 {
-                    cfPS(ctx, LOG_LEVEL_INFO, PROMISE_RESULT_INTERRUPTED, pp, a, "The device under '%s' cannot be removed from '%s'",
+                    cfPS(ctx, LOG_LEVEL_ERR, PROMISE_RESULT_INTERRUPTED, pp, a, "The device under '%s' cannot be removed from '%s'",
                          mountpt, VFSTAB[VSYSTEMHARDCLASS]);
                     *result = PromiseResultUpdate(*result, PROMISE_RESULT_INTERRUPTED);
                     free(line);