e1_input.c: Replace '.' in counter names with ':'

The '.' is illegal character in counter names, as they are exported
via CTRL interface, where '.' has a special meaning that cannot be
used by strings comprising the variable name.

Change-Id: I730d1acdd5562cd2c1758ceee31193010b14337d
diff --git a/src/e1_input.c b/src/e1_input.c
index 11949a1..4717830 100644
--- a/src/e1_input.c
+++ b/src/e1_input.c
@@ -58,13 +58,13 @@
 
 static const struct rate_ctr_desc e1inp_ctr_d[] = {
 	[E1I_CTR_HDLC_ABORT]  = {
-		"hdlc.abort", 	"HDLC abort"
+		"hdlc:abort", 	"HDLC abort"
 	},
 	[E1I_CTR_HDLC_BADFCS] = {
-		"hdlc.bad_fcs",	"HLDC Bad FCS"
+		"hdlc:bad_fcs",	"HLDC Bad FCS"
 	},
 	[E1I_CTR_HDLC_OVERR]  = {
-		"hdlc.overrun",	"HDLC Overrun"
+		"hdlc:overrun",	"HDLC Overrun"
 	},
 	[E1I_CTR_ALARM] = {
 		"alarm", 	"Alarm"