checksrc: disallow atoi and atol globally

No longer used in core and test code.

Also: allowlist in docs/examples.

Closes #19508

docs/examples/.checksrc

@@ -2,6 +2,8 @@
 #
 # SPDX-License-Identifier: curl
 
+allowfunc atoi
+allowfunc atol
 allowfunc fclose
 allowfunc fdopen
 allowfunc fopen

scripts/checksrc.pl

@@ -72,6 +72,8 @@ my %banfunc = (
     "strtok_r" => 1,
     "strtol" => 1,
     "strtoul" => 1,
+    "atoi" => 1,
+    "atol" => 1,
     "_mbscat" => 1,
     "_mbsncat" => 1,
     "_tcscat" => 1,

src/.checksrc

@@ -3,4 +3,3 @@
 # SPDX-License-Identifier: curl
 
 enable STDERR
-banfunc atoi