Fix some nonsense came from LGTM (#9962)

1. Local variable 's' hides a parameter of the same name.
```
int anetTcpAccept(char *err, int s, char *ip, size_t ip_len, int *port) {
    if ((fd = anetGenericAccept(err,s,(struct sockaddr*)&sa,&salen)) == ANET_ERR){}
}
```
Change the parameter name from `s` to `serversock`,
also unified with the header file definition.

2. Comparison is always false because i <= 48.
```
for (i = 0; i < DICT_STATS_VECTLEN-1; i++) {  // i < 49
    (i == DICT_STATS_VECTLEN-1)?">= ":"",  // i == 49
}
```
`i == DICT_STATS_VECTLEN-1` always result false, it is a dead code.

3. Empty block without comment.
`else if (!strcasecmp(opt,"ch")) {}`, add a comment to avoid warnings.

4. Bit field fill of type int should have explicitly unsigned integral, explicitly signed integral, or enumeration type.
Modify `int fill: QL_FILL_BITS;` to `unsigned int fill: QL_FILL_BITS;`

5. The result of this call to reconnectingRedisCommand is not checked for null, but 80% of calls to reconnectingRedisCommand check for null.
Just a cleanup job like others.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/quicklist.h b/src/quicklist.h
index 14c53ca4c..04136a733 100644
--- a/src/quicklist.h
+++ b/src/quicklist.h
@@ -107,7 +107,7 @@ typedef struct quicklist {
     quicklistNode *tail;
     unsigned long count;        /* total count of all entries in all listpacks */
     unsigned long len;          /* number of quicklistNodes */
-    int fill : QL_FILL_BITS;              /* fill factor for individual nodes */
+    unsigned int fill : QL_FILL_BITS;     /* fill factor for individual nodes */
     unsigned int compress : QL_COMP_BITS; /* depth of end nodes not to compress;0=off */
     unsigned int bookmark_count: QL_BM_BITS;
     quicklistBookmark bookmarks[];