Fix compiler with -Werror,-Wpointer-sign

nss/lib/certdb/genname.c

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "plarena.h"
 #include "seccomon.h"
 #include "secitem.h"
 #include "secoidt.h"
 #include "secasn1.h"
 #include "secder.h"
@@ skipping 1593 matching lines @@
                                  "\x50\x61\x72\x69\x73\x31\x10\x30\x0E\x06\x03"
                                  "\x55\x04\x0A\x13\x07\x50\x4D\x2F\x53\x47\x44"
                                  "\x4E\x31\x0E\x30\x0C\x06\x03\x55\x04\x0B\x13"
                                  "\x05\x44\x43\x53\x53\x49\x31\x0E\x30\x0C\x06"
                                  "\x03\x55\x04\x03\x13\x05\x49\x47\x43\x2F\x41"
                                  "\x31\x23\x30\x21\x06\x09\x2A\x86\x48\x86\xF7"
                                  "\x0D\x01\x09\x01\x16\x14\x69\x67\x63\x61\x40"
                                  "\x73\x67\x64\x6E\x2E\x70\x6D\x2E\x67\x6F\x75"
                                  "\x76\x2E\x66\x72";
 
-  const SECItem anssi_subject = {0, (char *) rawANSSISubject,
+  const SECItem anssi_subject = {0, (unsigned char *) rawANSSISubject,
                                  sizeof(rawANSSISubject)-1};
-  const SECItem permitFranceGovNC = {0, (char *) constraintFranceGov,
+  const SECItem permitFranceGovNC = {0, (unsigned char *) constraintFranceGov,
                                      sizeof(constraintFranceGov)-1};
 
   if (SECITEM_ItemsAreEqual(&cert->derSubject, &anssi_subject)) {
     SECStatus rv;
     rv = SECITEM_CopyItem(NULL, extensions, &permitFranceGovNC);
     return rv;
   }
   PORT_SetError(SEC_ERROR_EXTENSION_NOT_FOUND);
   return SECFailure;
 }
@@ skipping 334 matching lines @@
             break;
         }
         list->name = cert_CombineNamesLists(list->name, name);
         list->len++;
 done:
         PZ_Unlock(list->lock);
     }
     return;
 }
 #endif