cosmetic: prepend DB_STMT_ to enum stmt_idx entries

There are upcoming additions, and some seem too general without a proper common
prefix in the identifiers, like 'CREATE'.

Change-Id: I51b677db31a1ebbbc45dc7925074de7493fbde1f
diff --git a/src/db.c b/src/db.c
index aaf6fe2..6566527 100644
--- a/src/db.c
+++ b/src/db.c
@@ -26,15 +26,15 @@
 #include "db.h"
 
 static const char *stmt_sql[] = {
-	[SEL_BY_IMSI] = "SELECT id,imsi,msisdn,vlr_number,sgsn_number,sgsn_address,periodic_lu_tmr,periodic_rau_tau_tmr,nam_cs,nam_ps,lmsi,ms_purged_cs,ms_purged_ps FROM subscriber WHERE imsi = ?",
-	[UPD_VLR_BY_ID] = "UPDATE subscriber SET vlr_number = ? WHERE id = ?",
-	[UPD_SGSN_BY_ID] = "UPDATE subscriber SET sgsn_number = ? WHERE id = ?",
-	[AUC_BY_IMSI] = "SELECT id, algo_id_2g, ki, algo_id_3g, k, op, opc, sqn, ind_bitlen FROM subscriber LEFT JOIN auc_2g ON auc_2g.subscriber_id = subscriber.id LEFT JOIN auc_3g ON auc_3g.subscriber_id = subscriber.id WHERE imsi = ?",
-	[AUC_UPD_SQN] = "UPDATE auc_3g SET sqn = ? WHERE subscriber_id = ?",
-	[UPD_PURGE_CS_BY_IMSI] = "UPDATE subscriber SET ms_purged_cs=1 WHERE imsi = ?",
-	[UPD_PURGE_PS_BY_IMSI] = "UPDATE subscriber SET ms_purged_ps=1 WHERE imsi = ?",
-	[SET_NAM_PS_BY_IMSI] = "UPDATE subscriber SET nam_ps=1 WHERE imsi = ?",
-	[UNSET_NAM_PS_BY_IMSI] = "UPDATE subscriber SET nam_ps=0 WHERE imsi = ?",
+	[DB_STMT_SEL_BY_IMSI] = "SELECT id,imsi,msisdn,vlr_number,sgsn_number,sgsn_address,periodic_lu_tmr,periodic_rau_tau_tmr,nam_cs,nam_ps,lmsi,ms_purged_cs,ms_purged_ps FROM subscriber WHERE imsi = ?",
+	[DB_STMT_UPD_VLR_BY_ID] = "UPDATE subscriber SET vlr_number = ? WHERE id = ?",
+	[DB_STMT_UPD_SGSN_BY_ID] = "UPDATE subscriber SET sgsn_number = ? WHERE id = ?",
+	[DB_STMT_AUC_BY_IMSI] = "SELECT id, algo_id_2g, ki, algo_id_3g, k, op, opc, sqn, ind_bitlen FROM subscriber LEFT JOIN auc_2g ON auc_2g.subscriber_id = subscriber.id LEFT JOIN auc_3g ON auc_3g.subscriber_id = subscriber.id WHERE imsi = ?",
+	[DB_STMT_AUC_UPD_SQN] = "UPDATE auc_3g SET sqn = ? WHERE subscriber_id = ?",
+	[DB_STMT_UPD_PURGE_CS_BY_IMSI] = "UPDATE subscriber SET ms_purged_cs=1 WHERE imsi = ?",
+	[DB_STMT_UPD_PURGE_PS_BY_IMSI] = "UPDATE subscriber SET ms_purged_ps=1 WHERE imsi = ?",
+	[DB_STMT_SET_NAM_PS_BY_IMSI] = "UPDATE subscriber SET nam_ps=1 WHERE imsi = ?",
+	[DB_STMT_UNSET_NAM_PS_BY_IMSI] = "UPDATE subscriber SET nam_ps=0 WHERE imsi = ?",
 };
 
 static void sql3_error_log_cb(void *arg, int err_code, const char *msg)