[PATCH] block: Fix compilation with CentOS 6

[Andrew Cooper]

GCC 4.4 from CentOS 6 chokes in the following way:

src/hw/blockcmd.c: In function 'scsi_rep_luns_scan':
  src/hw/blockcmd.c:229: error: unknown field 'cdbcmd' specified in initializer
  src/hw/blockcmd.c:229: warning: missing braces around initializer
  src/hw/blockcmd.c:229: warning: (near initialization for 'op.<anonymous>')
  src/hw/blockcmd.c:229: warning: initialization makes integer from pointer without a cast

Avoid using an initialiser list.

Signed-off-by: Andrew Cooper 
---
Discovered while adding CentOS 6 to Xen's CI system.  If this patch is
acceptable, what are the chances of having it backported to 1.12-stable ?
---
 src/hw/blockcmd.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/hw/blockcmd.c b/src/hw/blockcmd.c
index 1f15081..a40f37c 100644
--- a/src/hw/blockcmd.c
+++ b/src/hw/blockcmd.c
@@ -222,16 +222,17 @@ int scsi_rep_luns_scan(struct drive_s *tmp_drive, scsi_add_lun add_lun)
     struct cdb_report_luns cdb = {
         .command = CDB_CMD_REPORT_LUNS,
     };
-    struct disk_op_s op = {
-        .drive_fl = tmp_drive,
-        .command = CMD_SCSI,
-        .count = 1,
-        .cdbcmd = &cdb,
-    };
+    /* GCC 4.4 (CentOS 6) can't initialise anonymous unions. */
+    struct disk_op_s op = {};
     struct cdbres_report_luns *resp;

ASSERT32FLAT();

+    op.drive_fl = tmp_drive;
+    op.command = CMD_SCSI;
+    op.count = 1;
+    op.cdbcmd = &cdb;
+
     while (1) {
         op.blocksize = sizeof(struct cdbres_report_luns) +
             maxluns * sizeof(struct scsi_lun);