virLogManagerDomainReadLogFile: Don't do dummy allocs

Since we pass dummy variables @fdout and @fdoutlen into
virNetClientProgramCall() we make it alloc @fdout array (even
though it's an array of 0 elements since vitlogd can hardly pass
us some FDs at this stage). Nevertheless, it's an allocation not
followed by free():

==29385== 0 bytes in 60 blocks are definitely lost in loss record 2 of 1,009
==29385==    at 0x4C2C070: calloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==29385==    by 0x54B99EF: virAllocN (viralloc.c:191)
==29385==    by 0x56821B1: virNetClientProgramCall (virnetclientprogram.c:359)
==29385==    by 0x563B304: virLogManagerDomainReadLogFile (log_manager.c:272)
==29385==    by 0x217CD613: qemuDomainLogContextRead (qemu_domain.c:2485)
==29385==    by 0x217EDC76: qemuProcessReadLog (qemu_process.c:1660)
==29385==    by 0x217EDE1D: qemuProcessReportLogError (qemu_process.c:1696)
==29385==    by 0x217EE8C1: qemuProcessWaitForMonitor (qemu_process.c:1957)
==29385==    by 0x217F6636: qemuProcessLaunch (qemu_process.c:4955)
==29385==    by 0x217F71A4: qemuProcessStart (qemu_process.c:5152)
==29385==    by 0x21846582: qemuDomainObjStart (qemu_driver.c:7396)
==29385==    by 0x218467DE: qemuDomainCreateWithFlags (qemu_driver.c:7450)
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
(cherry picked from commit c03fbecc)
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/logging/log_manager.c

@@ -256,8 +256,6 @@ virLogManagerDomainReadLogFile(virLogManagerPtr mgr,
 {
     struct virLogManagerProtocolDomainReadLogFileArgs args;
     struct virLogManagerProtocolDomainReadLogFileRet ret;
-    int *fdout = NULL;
-    size_t fdoutlen = 0;
     char *rv = NULL;
 
     memset(&args, 0, sizeof(args));
@@ -273,7 +271,7 @@ virLogManagerDomainReadLogFile(virLogManagerPtr mgr,
                                 mgr->client,
                                 mgr->serial++,
                                 VIR_LOG_MANAGER_PROTOCOL_PROC_DOMAIN_READ_LOG_FILE,
-                                0, NULL, &fdoutlen, &fdout,
+                                0, NULL, NULL, NULL,
                                 (xdrproc_t)xdr_virLogManagerProtocolDomainReadLogFileArgs, &args,
                                 (xdrproc_t)xdr_virLogManagerProtocolDomainReadLogFileRet, &ret) < 0)
         goto cleanup;