build: Rename util.{c,h} to calls-util.{c,h}

"util" is a very generic name. This guards against accidentally
including similarly named headers from elsewhere.

plugins/provider/sip/calls-sip-call.c

@@ -33,7 +33,7 @@
 #include "calls-sip-media-manager.h"
 #include "calls-sip-media-pipeline.h"
 #include "calls-sip-util.h"
-#include "util.h"
+#include "calls-util.h"
 
 #include <glib/gi18n.h>
 

plugins/provider/sip/calls-sip-media-manager.c

@@ -29,7 +29,7 @@
 #include "calls-sip-media-pipeline.h"
 #include "calls-srtp-utils.h"
 #include "gst-rfc3551.h"
-#include "util.h"
+#include "calls-util.h"
 
 #include <gio/gio.h>
 #include <gst/gst.h>

plugins/provider/sip/calls-sip-media-pipeline.c

@@ -29,7 +29,7 @@
 #include "calls-media-pipeline-enums.h"
 #include "calls-sip-media-pipeline.h"
 #include "calls-srtp-utils.h"
-#include "util.h"
+#include "calls-util.h"
 
 #include <glib-unix.h>
 #include <gst/gst.h>

plugins/provider/sip/calls-srtp-utils.c

@@ -23,7 +23,7 @@
  */
 
 #include "calls-srtp-utils.h"
-#include "util.h"
+#include "calls-util.h"
 
 #include <gio/gio.h>
 #include <sys/random.h>