Fix hex printing of negative numbers.

Change from this hex printout of -1...

rc: 0x-0000001

To this...

rc: 0xffffffff

Change-Id: I284de2a2f962b1199f216e6827c3140d2da09532
Signed-off-by: Michael Walsh <micwalsh@us.ibm.com>
diff --git a/lib/gen_print.py b/lib/gen_print.py
index 36c6fa5..ceb4103 100755
--- a/lib/gen_print.py
+++ b/lib/gen_print.py
@@ -601,7 +601,11 @@
             value_format = "%s"
         format_string = "%" + str(loc_col1_indent) + "s%-" \
             + str(loc_col1_width) + "s" + value_format + trailing_char
-        return format_string % ("", str(var_name) + ":", var_value)
+        if value_format == "0x%08x":
+            return format_string % ("", str(var_name) + ":",
+                                    var_value & 0xffffffff)
+        else:
+            return format_string % ("", str(var_name) + ":", var_value)
     elif type(var_value) is type:
         return sprint_varx(var_name, str(var_value).split("'")[1], hex,
                            loc_col1_indent, loc_col1_width, trailing_char)