qemu: command: Introduce qemuBuildGraphicsEGLHeadlessCommandLine helper

We're going to need a bit more logic for egl-headless down the road so
prepare a helper just like for the other display types.
Signed-off-by: NErik Skultety <eskultet@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_command.c

@@ -8307,6 +8307,19 @@ qemuBuildGraphicsSPICECommandLine(virQEMUDriverConfigPtr cfg,
 }
 
 
+static int
+qemuBuildGraphicsEGLHeadlessCommandLine(virQEMUDriverConfigPtr cfg ATTRIBUTE_UNUSED,
+                                        virCommandPtr cmd,
+                                        virQEMUCapsPtr qemuCaps ATTRIBUTE_UNUSED,
+                                        virDomainGraphicsDefPtr graphics ATTRIBUTE_UNUSED)
+{
+    virCommandAddArg(cmd, "-display");
+    virCommandAddArg(cmd, "egl-headless");
+
+    return 0;
+}
+
+
 static int
 qemuBuildGraphicsCommandLine(virQEMUDriverConfigPtr cfg,
                              virCommandPtr cmd,
@@ -8338,8 +8351,9 @@ qemuBuildGraphicsCommandLine(virQEMUDriverConfigPtr cfg,
 
             break;
         case VIR_DOMAIN_GRAPHICS_TYPE_EGL_HEADLESS:
-            virCommandAddArg(cmd, "-display");
-            virCommandAddArg(cmd, "egl-headless");
+            if (qemuBuildGraphicsEGLHeadlessCommandLine(cfg, cmd,
+                                                        qemuCaps, graphics) < 0)
+                return -1;
 
             break;
         case VIR_DOMAIN_GRAPHICS_TYPE_RDP: