[PATCH v2 3/5] x86: Add usage() to print out usage message

[Fouad Hilly <fouad.hilly@cloud.com>]

Refactor xen-ucode tool by adding usage() to handle usage\help messages
As we add more command options this will keep help\usage messages in common block

[v2]
1- Improved message description.
2- Fixed formatting and indentation.
3- Error message to print to stderr.

Signed-off-by: Fouad Hilly <fouad.hilly@cloud.com>
---
 tools/misc/xen-ucode.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/misc/xen-ucode.c b/tools/misc/xen-ucode.c
index c6ae6498d659..0c0b2337b4ea 100644
--- a/tools/misc/xen-ucode.c
+++ b/tools/misc/xen-ucode.c
@@ -17,6 +17,15 @@ static xc_interface *xch;
 static const char intel_id[] = "GenuineIntel";
 static const char   amd_id[] = "AuthenticAMD";
 
+static void usage(const char *name)
+{
+    printf("%s: Xen microcode updating tool\n"
+           "Usage: %s [microcode file] [options]\n"
+           "Options:\n"
+           "show-cou-info   show CPU information and exit\n",
+           name, name);
+}
+
 static void show_curr_cpu(FILE *f)
 {
     int ret;
-- 
2.42.0