[PATCH] lib/strtoul: fix MISRA R10.2 violation

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

Fix last violation of R10.2 by casting the result of toupper to plain
char. Note that we don't want to change toupper itself as it is a legacy
interface and it would cause more issues.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx>
---
I believe this is the last R10.2 violation

diff --git a/xen/lib/strtoul.c b/xen/lib/strtoul.c
index a378fe735e..345dcf9d8c 100644
--- a/xen/lib/strtoul.c
+++ b/xen/lib/strtoul.c
@@ -38,7 +38,7 @@ unsigned long simple_strtoul(
 
     while ( isxdigit(*cp) &&
             (value = isdigit(*cp) ? *cp - '0'
-                                  : toupper(*cp) - 'A' + 10) < base )
+                                  : (char)toupper(*cp) - 'A' + 10) < base )
     {
         result = result * base + value;
         cp++;