char: rename qemu_chr_reset to qemu_chr_generic_open

This function sends out the OPENED event to backends that
have drive the chardevs. The 'reset' is now a historical
artifact and we can now just call the function for what it
is.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/console.c b/console.c
index 9bbef59..82ddbe4 100644
--- a/console.c
+++ b/console.c
@@ -1384,7 +1384,7 @@
     s->t_attrib = s->t_attrib_default;
     text_console_resize(s);
 
-    qemu_chr_reset(chr);
+    qemu_chr_generic_open(chr);
     if (chr->init)
         chr->init(chr);
 }