conf: virDomainDiskDefIotuneParse: Report malformed number errors

Rest of the fields of the iotune data structure did not check for
malformed integers. Use the previously defined macro to extract them
which will simplify the code and add error reporting.

src/conf/domain_conf.c

@@ -6699,48 +6699,14 @@ virDomainDiskDefIotuneParse(virDomainDiskDefPtr def,
     PARSE_IOTUNE(read_iops_sec);
     PARSE_IOTUNE(write_iops_sec);
 
-    if (virXPathULongLong("string(./iotune/total_bytes_sec_max)",
-                          ctxt,
-                          &def->blkdeviotune.total_bytes_sec_max) < 0) {
-        def->blkdeviotune.total_bytes_sec_max = 0;
-    }
-
-    if (virXPathULongLong("string(./iotune/read_bytes_sec_max)",
-                          ctxt,
-                          &def->blkdeviotune.read_bytes_sec_max) < 0) {
-        def->blkdeviotune.read_bytes_sec_max = 0;
-    }
-
-    if (virXPathULongLong("string(./iotune/write_bytes_sec_max)",
-                          ctxt,
-                          &def->blkdeviotune.write_bytes_sec_max) < 0) {
-        def->blkdeviotune.write_bytes_sec_max = 0;
-    }
-
-    if (virXPathULongLong("string(./iotune/total_iops_sec_max)",
-                          ctxt,
-                          &def->blkdeviotune.total_iops_sec_max) < 0) {
-        def->blkdeviotune.total_iops_sec_max = 0;
-    }
-
-    if (virXPathULongLong("string(./iotune/read_iops_sec_max)",
-                          ctxt,
-                          &def->blkdeviotune.read_iops_sec_max) < 0) {
-        def->blkdeviotune.read_iops_sec_max = 0;
-    }
-
-    if (virXPathULongLong("string(./iotune/write_iops_sec_max)",
-                          ctxt,
-                          &def->blkdeviotune.write_iops_sec_max) < 0) {
-        def->blkdeviotune.write_iops_sec_max = 0;
-    }
-
-    if (virXPathULongLong("string(./iotune/size_iops_sec)",
-                          ctxt,
-                          &def->blkdeviotune.size_iops_sec) < 0) {
-        def->blkdeviotune.size_iops_sec = 0;
-    }
-
+    PARSE_IOTUNE(total_bytes_sec_max);
+    PARSE_IOTUNE(read_bytes_sec_max);
+    PARSE_IOTUNE(write_bytes_sec_max);
+    PARSE_IOTUNE(total_iops_sec_max);
+    PARSE_IOTUNE(read_iops_sec_max);
+    PARSE_IOTUNE(write_iops_sec_max);
+
+    PARSE_IOTUNE(size_iops_sec);
 
     if ((def->blkdeviotune.total_bytes_sec &&
          def->blkdeviotune.read_bytes_sec) ||