cosmetic: fix spelling in logging messages: existAnt -> existEnt

Change-Id: Ifb22b5544cf06012fa529828dfdf3f0d73b07e7d
diff --git a/src/input/dahdi.c b/src/input/dahdi.c
index 55abc7c..ce9dfc1 100644
--- a/src/input/dahdi.c
+++ b/src/input/dahdi.c
@@ -526,7 +526,7 @@
 
 	scfg = span_cfgs[line->port_nr];
 	if (!scfg) {
-		vty_out(vty, "DAHDI Span %u non-existant%s",
+		vty_out(vty, "DAHDI Span %u non-existent%s",
 			line->port_nr+1, VTY_NEWLINE);
 		return;
 	}