tidy-up: curlx/nonblock.h includes

Delete where unused, include where to used to avoid relying on
side-effect of other headers.

Also: delete "for curlx_nonblock" comments. That's the only symbol
offered by this header.

Closes #20055

lib/cf-ip-happy.h

@@ -25,8 +25,6 @@
  ***************************************************************************/
 #include "curl_setup.h"
 
-#include "curlx/nonblock.h" /* for curlx_nonblock() */
-
 /**
  * Create a cfilter for making an "ip" connection to the
  * given address, using parameters from `conn`. The "ip" connection

lib/cf-socket.c

@@ -72,6 +72,7 @@
 #include "rand.h"
 #include "strdup.h"
 #include "system_win32.h"
+#include "curlx/nonblock.h"
 #include "curlx/version_win32.h"
 #include "curlx/strerr.h"
 #include "curlx/strparse.h"

lib/cf-socket.h

@@ -25,7 +25,6 @@
  ***************************************************************************/
 #include "curl_setup.h"
 
-#include "curlx/nonblock.h" /* for curlx_nonblock() */
 #include "sockaddr.h" /* required for Curl_sockaddr_storage */
 
 struct Curl_addrinfo;

lib/connect.h

@@ -25,7 +25,6 @@
  ***************************************************************************/
 #include "curl_setup.h"
 
-#include "curlx/nonblock.h" /* for curlx_nonblock() */
 #include "curlx/timeval.h"
 
 struct Curl_dns_entry;

lib/curl_rtmp.c

@@ -30,7 +30,7 @@
 #include "curl_rtmp.h"
 #include "urldata.h"
 #include "url.h"
-#include "curlx/nonblock.h" /* for curlx_nonblock */
+#include "curlx/nonblock.h"
 #include "progress.h" /* for Curl_pgrsSetUploadSize */
 #include "transfer.h"
 #include "bufref.h"

lib/socketpair.c

@@ -23,9 +23,11 @@
  ***************************************************************************/
 
 #include "curl_setup.h"
+
 #include "socketpair.h"
 #include "urldata.h"
 #include "rand.h"
+#include "curlx/nonblock.h"
 
 #ifdef USE_EVENTFD
 
@@ -122,7 +124,6 @@ int Curl_socketpair(int domain, int type, int protocol,
 #define INADDR_LOOPBACK 0x7f000001
 #endif
 
-#include "curlx/nonblock.h" /* for curlx_nonblock */
 #include "curlx/timeval.h"  /* needed before select.h */
 #include "select.h"   /* for Curl_poll */
 

lib/socks_gssapi.c

@@ -32,6 +32,7 @@
 #include "sendf.h"
 #include "cfilters.h"
 #include "connect.h"
+#include "curlx/nonblock.h"
 #include "curlx/timeval.h"
 #include "socks.h"
 #include "curlx/warnless.h"

lib/socks_sspi.c

@@ -32,6 +32,7 @@
 #include "cfilters.h"
 #include "connect.h"
 #include "strerror.h"
+#include "curlx/nonblock.h"
 #include "curlx/timeval.h"
 #include "socks.h"
 #include "curl_sspi.h"

lib/ws.c

@@ -38,7 +38,6 @@
 #include "easyif.h"
 #include "transfer.h"
 #include "select.h"
-#include "curlx/nonblock.h"
 #include "curlx/strparse.h"
 #include "curlx/warnless.h"