curl.1: Fix cmdline-opts reference errors.

--data, --form, and --ntlm were declared to be mutually exclusive with
non-existing options. --data and --form referred to --upload (which is
short for --upload-file and therefore did work, so this one was merely
a bit confusing), --ntlm referred to --negotiated instead of --negotiate.

Closes #2612

docs/cmdline-opts/data.d

@@ -4,7 +4,7 @@ Arg: <data>
 Help: HTTP POST data
 Protocols: HTTP
 See-also: data-binary data-urlencode data-raw
-Mutexed: form head upload
+Mutexed: form head upload-file
 ---
 Sends the specified data in a POST request to the HTTP server, in the same way
 that a browser does when a user has filled in an HTML form and presses the

docs/cmdline-opts/form.d

@@ -3,7 +3,7 @@ Short: F
 Arg: <name=content>
 Help: Specify multipart MIME data
 Protocols: HTTP SMTP IMAP
-Mutexed: data head upload
+Mutexed: data head upload-file
 ---
 For HTTP protocol family, this lets curl emulate a filled-in form in which a
 user has pressed the submit button. This causes curl to POST data using the

docs/cmdline-opts/ntlm.d

@@ -1,6 +1,6 @@
 Long: ntlm
 Help: Use HTTP NTLM authentication
-Mutexed: basic negotiated digest anyauth
+Mutexed: basic negotiate digest anyauth
 See-also: proxy-ntlm
 Protocols: HTTP
 Requires: TLS