user_channel: Update the log of invalid channels

When the channel is invalid, redundant logs will be recorded:
```
Channel is not valid
Invalid channel
```
So the log in the isValidChannel method is deleted and the caller is
responsible for recording.

Change-Id: I190e9d428e9e6870e4cab4c571cf9ffd1e7caea1
Signed-off-by: George Liu <liuxiwei@ieisystem.com>
diff --git a/user_channel/user_layer.cpp b/user_channel/user_layer.cpp
index 5a2e7e0..ee147d8 100644
--- a/user_channel/user_layer.cpp
+++ b/user_channel/user_layer.cpp
@@ -143,6 +143,8 @@
 {
     if (!UserAccess::isValidChannel(chNum))
     {
+        lg2::error("Get Privilege access - Invalid channel number: {CHANNEL}",
+                   "CHANNEL", chNum);
         return ccInvalidFieldRequest;
     }
     if (!UserAccess::isValidUserId(userId))
@@ -186,6 +188,9 @@
 {
     if (!UserAccess::isValidChannel(chNum))
     {
+        lg2::error(
+            "Set user payload access - Invalid channel number: {CHANNEL}",
+            "CHANNEL", chNum);
         return ccInvalidFieldRequest;
     }
     if (!UserAccess::isValidUserId(userId))
@@ -202,6 +207,9 @@
 {
     if (!UserAccess::isValidChannel(chNum))
     {
+        lg2::error(
+            "Get user payload access - Invalid channel number: {CHANNEL}",
+            "CHANNEL", chNum);
         return ccInvalidFieldRequest;
     }
     if (!UserAccess::isValidUserId(userId))