Fix segfault on screendump with -nographic

When running -nographic and calling "screendump" on the monitor, qemu
segfaults. Fix the invalid pointer dereference by checking for NULL.

Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/console.c b/console.c
index 871c1d47b..9c6addf8e 100644
--- a/console.c
+++ b/console.c
@@ -180,7 +180,7 @@ void vga_hw_screen_dump(const char *filename)
     active_console = consoles[0];
     /* There is currently no way of specifying which screen we want to dump,
        so always dump the first one.  */
-    if (consoles[0]->hw_screen_dump)
+    if (consoles[0] && consoles[0]->hw_screen_dump)
         consoles[0]->hw_screen_dump(consoles[0]->hw, filename);
     active_console = previous_active_console;
 }