qcacmn: Specify the size of array dbgid-strings as WLAN_REF_ID_MAX

Currently, size of the array to return dbgids in string format is
not specified explicitly. This array is expected to be updated
with the corresponding string when a dbgid is added in the
enum wlan_objmgr_ref_dbgid. Any miss in the updation would lead
to array out of bound access as the API string_from_dbgid()
tries get string corresponds to the newly added dbgid also.
Specify the maximum possible size as WLAN_REF_ID_MAX explicitly,
so that it returns "null" if the string corresponds a dbgid
is not defined.
Return the string only if the id matches or return "Unknown".

Change-Id: I1c835b8e9d681bf23f1bce866aa523cb41b9a134
CRs-Fixed: 2702696

umac/cmn_services/obj_mgr/inc/wlan_objmgr_cmn.h

@@ -360,9 +360,9 @@ typedef enum {
  * Please note to add new string in the array at index equal to
  * its enum value in wlan_objmgr_ref_dbgid.
  */
-static inline char *string_from_dbgid(wlan_objmgr_ref_dbgid id)
+static inline const char *string_from_dbgid(wlan_objmgr_ref_dbgid id)
 {
-	static const char *strings[] = { "WLAN_OBJMGR_ID",
+	static const char *strings[WLAN_REF_ID_MAX] = { "WLAN_OBJMGR_ID",
 					"WLAN_MLME_SB_ID",
 					"WLAN_MLME_NB_ID",
 					"WLAN_MGMT_SB_ID",
@@ -437,10 +437,12 @@ static inline char *string_from_dbgid(wlan_objmgr_ref_dbgid id)
 					"WLAN_PSOC_TARGET_IF_ID",
 					"FTM_TIME_SYNC_ID",
 					"WLAN_PKT_CAPTURE_ID",
-					"WLAN_DCS_ID",
-					"WLAN_REF_ID_MAX"};
+					"WLAN_DCS_ID"};
 
-	return (char *)strings[id];
+	if (id >= WLAN_REF_ID_MAX)
+		return "Unknown";
+
+	return strings[id];
 }
 
 #ifdef WLAN_OBJMGR_DEBUG