clang-tidy: sync argument names in prototype and definition

Discovered with clang-tidy checker
`readability-inconsistent-declaration-parameter-name`.

Also:
- do not enforce the above because of inconsistencies still present
  between public API prototypes and definitions. (Also betwen man page
  protos, and man page examples, and other parts of the code, e.g.
  `easy` vs `curl` vs `d` vs `handle`) Perhaps subject for a future
  effort:
  https://github.com/curl/curl/actions/runs/22166472728/job/64094691653
- enable and fix `readability-named-parameter` where missing.

Refs:
https://clang.llvm.org/extra/clang-tidy/checks/readability/inconsistent-declaration-parameter-name.html
https://clang.llvm.org/extra/clang-tidy/checks/readability/named-parameter.html

Closes #20624

src/tool_getpass.c

@@ -162,7 +162,7 @@ static bool ttyecho(bool enable, int fd)
 }
 
 char *getpass_r(const char *prompt, /* prompt to display */
-                char *password,     /* buffer to store password in */
+                char *buffer,       /* buffer to store password in */
                 size_t buflen)      /* size of buffer to store password in */
 {
   ssize_t nread;
@@ -174,11 +174,11 @@ char *getpass_r(const char *prompt, /* prompt to display */
   disabled = ttyecho(FALSE, fd); /* disable terminal echo */
 
   fputs(prompt, tool_stderr);
-  nread = read(fd, password, buflen);
+  nread = read(fd, buffer, buflen);
   if(nread > 0)
-    password[--nread] = '\0'; /* null-terminate where enter is stored */
+    buffer[--nread] = '\0'; /* null-terminate where enter is stored */
   else
-    password[0] = '\0'; /* got nothing */
+    buffer[0] = '\0'; /* got nothing */
 
   if(disabled) {
     /* if echo actually was disabled, add a newline */
@@ -189,7 +189,7 @@ char *getpass_r(const char *prompt, /* prompt to display */
   if(STDIN_FILENO != fd)
     curlx_close(fd);
 
-  return password; /* return pointer to buffer */
+  return buffer; /* return pointer to buffer */
 }
 
 #endif /* DONE */