patch 9.1.1514: Coverity complains about the use of tmpfile()

Problem:  coverity complains about the use of tmpfile()
Solution: use vim_tempname() instead to create anonym file

related: #17097
closes: #17674

Signed-off-by: Christian Brabandt <cb@256bit.org>

src/os_unix.c

@@ -8940,13 +8940,24 @@ mch_create_anon_file(void)
 	fd = shm_open(template, O_CREAT | O_RDWR | O_EXCL, 0600);
 
 	if (fd >= 0 || errno != EEXIST)
-	    break; }
+	    break;
+    }
     // Remove object name from namespace
     shm_unlink(template);
 #endif
+    // Last resort
     if (fd == -1)
-	// Last resort
+    {
-	fd = fileno(tmpfile());
+	char_u	*tempname;
-
+	// get a name for the temp file
+	if ((tempname = vim_tempname('w', FALSE)) == NULL)
+	{
+	    emsg(_(e_cant_get_temp_file_name));
+	    return -1;
+	}
+	fd = mch_open((char *)tempname, O_CREAT | O_RDWR | O_EXCL, 0600);
+	mch_remove(tempname);
+	vim_free(tempname);
+    }
     return fd;
 }

src/version.c

@@ -719,6 +719,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1514,
 /**/
     1513,
 /**/