[PATCH] xl: Clarify 'xend is running' error message

[George Dunlap <george.dunlap@eu.citrix.com>]

# HG changeset patch
# User George Dunlap <george.dunlap@eu.citrix.com>
# Date 1340285415 -3600
# Node ID 849fe346b05a3265894e6ce16292f81def92fce7
# Parent  baa85434d0ec16629ca30b7c07deaa9beb3ea9c5
xl: Clarify 'xend is running' error message

* Give reason for check (unpredictable results)
* Give a better recommendation (shut down xend)
* Make it clear that -f is overriding a safety check.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>

diff --git a/tools/libxl/xl.c b/tools/libxl/xl.c
--- a/tools/libxl/xl.c
+++ b/tools/libxl/xl.c
@@ -251,9 +251,9 @@ int main(int argc, char **argv)
             for (int i = 0; i < sizeof(locks)/sizeof(locks[0]); i++) {
                 if (!access(locks[i], F_OK) && !force_execution) {
                     fprintf(stderr,
-"xend is running, which prevents xl from working correctly.\n"
-"If you still want to force the execution of xl please use the -f\n"
-"option.\n"
+"xend is running, which may cause unpredictable results when using\n"
+"this xl command.  Please shut down xend before continuing.\n\n"
+"(This check can be overridden with the -f option.)\n"
                             );
                     ret = 1;
                     goto xit;