conf: Remove ATTRIBUTE_NONNULL(2) from virDomainCheckDeviceChanges()

Since we are checking the 2nd parameter in the function for NULL,
we need to remove ATTRIBUTE_NONNULL(2) from the prototype.
Signed-off-by: NStefan Berger <stefanb@linux.ibm.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>
Message-Id: <20190726205633.2041912-5-stefanb@linux.vnet.ibm.com>

src/conf/domain_conf.h

@@ -3638,5 +3638,4 @@ bool
 virDomainGraphicsNeedsAutoRenderNode(const virDomainGraphicsDef *graphics);
 
 int
-virDomainCheckDeviceChanges(virDomainDefPtr def, virDomainDefPtr newDef)
-    ATTRIBUTE_NONNULL(2);
+virDomainCheckDeviceChanges(virDomainDefPtr def, virDomainDefPtr newDef);