qemu-io: Use error_[gs]et_progname()

qemu-io reimplements itself what
error_get_progname()/error_set_progname() already does.
This commit switches it to use this API from qemu-error.h

Signed-off-by: Christophe Fergeau <cfergeau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20190131164614.19209-2-cfergeau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qemu-io.c

@@ -34,8 +34,6 @@
 
 #define CMD_NOFILE_OK   0x01
 
-static char *progname;
-
 static BlockBackend *qemuio_blk;
 static bool quit_qemu_io;
 
@@ -312,7 +310,7 @@ static char *get_prompt(void)
     static char prompt[FILENAME_MAX + 2 /*"> "*/ + 1 /*"\0"*/ ];
 
     if (!prompt[0]) {
-        snprintf(prompt, sizeof(prompt), "%s> ", progname);
+        snprintf(prompt, sizeof(prompt), "%s> ", error_get_progname());
     }
 
     return prompt;
@@ -525,7 +523,7 @@ int main(int argc, char **argv)
 #endif
 
     module_call_init(MODULE_INIT_TRACE);
-    progname = g_path_get_basename(argv[0]);
+    error_set_progname(argv[0]);
     qemu_init_exec_dir(argv[0]);
 
     qcrypto_init(&error_fatal);
@@ -580,10 +578,10 @@ int main(int argc, char **argv)
             break;
         case 'V':
             printf("%s version " QEMU_FULL_VERSION "\n"
-                   QEMU_COPYRIGHT "\n", progname);
+                   QEMU_COPYRIGHT "\n", error_get_progname());
             exit(0);
         case 'h':
-            usage(progname);
+            usage(error_get_progname());
             exit(0);
         case 'U':
             force_share = true;
@@ -600,13 +598,13 @@ int main(int argc, char **argv)
             imageOpts = true;
             break;
         default:
-            usage(progname);
+            usage(error_get_progname());
             exit(1);
         }
     }
 
     if ((argc - optind) > 1) {
-        usage(progname);
+        usage(error_get_progname());
         exit(1);
     }