Fix compiler with -Werror,-Wpointer-sign

nss/lib/certdb/genname.c

Index: nss/lib/certdb/genname.c
diff --git a/nss/lib/certdb/genname.c b/nss/lib/certdb/genname.c
index 412a9d2c6b165513b1ca785409c93d4631089db8..1b0cc970489478dc36bd9a4c38d8bca6231eb9b3 100644
--- a/nss/lib/certdb/genname.c
+++ b/nss/lib/certdb/genname.c
@@ -1611,9 +1611,9 @@ getNameExtensionsBuiltIn(CERTCertificate  *cert,
                                  "\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)) {