build: fix build with older gcc

gcc 4.1.2 (hello, RHEL 5!) fails to build on 32-bit platforms with:

conf/domain_conf.c: In function 'virDomainDefParseXML':
conf/domain_conf.c:10581: warning: integer constant is too large for 'long' type

Problem introduced in commit f8e3221f.

* src/conf/domain_conf.c (virDomainDefParseXML): Mark large constants.
Signed-off-by: NEric Blake <eblake@redhat.com>

src/conf/domain_conf.c

@@ -10578,7 +10578,7 @@ virDomainDefParseXML(xmlDocPtr xml,
 
     if (def->cputune.quota > 0 &&
         (def->cputune.quota < 1000 ||
-         def->cputune.quota > 18446744073709551)) {
+         def->cputune.quota > 18446744073709551LL)) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                        _("Value of cputune quota must be in range "
                          "[1000, 18446744073709551]"));
@@ -10610,7 +10610,7 @@ virDomainDefParseXML(xmlDocPtr xml,
 
     if (def->cputune.emulator_quota > 0 &&
         (def->cputune.emulator_quota < 1000 ||
-         def->cputune.emulator_quota > 18446744073709551)) {
+         def->cputune.emulator_quota > 18446744073709551LL)) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                        _("Value of cputune emulator_quota must be in range "
                          "[1000, 18446744073709551]"));