Fix a memory leak in the qemudBuildCommandLine.

ADD_ARG_LIT should only be used for literal arguments,
since it duplicates the memory.  Since virBufferContentAndReset
is already allocating memory, we should only use ADD_ARG.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

src/qemu/qemu_conf.c

@@ -4110,7 +4110,7 @@ int qemudBuildCommandLine(virConnectPtr conn,
                 goto error;
             }
 
-            ADD_ARG_LIT(virBufferContentAndReset(&boot_buf));
+            ADD_ARG(virBufferContentAndReset(&boot_buf));
         }
 
         if (def->os.kernel) {