virDomainObjGetShortName: take virDomainDef

So far this function takes virDomainObjPtr which:
1) is an overkill,
2) might be not available in all the places we will use it.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/conf/domain_conf.c

@@ -25701,13 +25701,13 @@ virDomainDefHasMemballoon(const virDomainDef *def)
  * Shorten domain name to avoid possible path length limitations.
  */
 char *
-virDomainObjGetShortName(virDomainObjPtr vm)
+virDomainObjGetShortName(const virDomainDef *def)
 {
     const int dommaxlen = 20;
     char *ret = NULL;
 
     ignore_value(virAsprintf(&ret, "%d-%.*s",
-                             vm->def->id, dommaxlen, vm->def->name));
+                             def->id, dommaxlen, def->name));
 
     return ret;
 }

src/conf/domain_conf.h

@@ -3205,7 +3205,7 @@ int virDomainDefGetVcpuPinInfoHelper(virDomainDefPtr def,
 
 bool virDomainDefHasMemballoon(const virDomainDef *def) ATTRIBUTE_NONNULL(1);
 
-char *virDomainObjGetShortName(virDomainObjPtr vm);
+char *virDomainObjGetShortName(const virDomainDef *def) ATTRIBUTE_NONNULL(1);
 
 int
 virDomainGetBlkioParametersAssignFromDef(virDomainDefPtr def,

src/qemu/qemu_domain.c

@@ -1475,7 +1475,7 @@ qemuDomainSetPrivatePaths(virQEMUDriverPtr driver,
 {
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
     qemuDomainObjPrivatePtr priv = vm->privateData;
-    char *domname = virDomainObjGetShortName(vm);
+    char *domname = virDomainObjGetShortName(vm->def);
     int ret = -1;
 
     if (!domname)

src/qemu/qemu_driver.c

@@ -3885,7 +3885,7 @@ getAutoDumpPath(virQEMUDriverPtr driver,
                 virDomainObjPtr vm)
 {
     char *dumpfile = NULL;
-    char *domname = virDomainObjGetShortName(vm);
+    char *domname = virDomainObjGetShortName(vm->def);
     char timestr[100];
     struct tm time_info;
     time_t curtime = time(NULL);