patch 8.1.1414: alloc() returning "char_u *" causes a lot of type casts

Problem:    Alloc() returning "char_u *" causes a lot of type casts.
Solution:   Have it return "void *". (Mike Williams)  Define ALLOC_ONE() to
            check the simple allocations.
diff --git a/src/gui_x11.c b/src/gui_x11.c
index 0188138..edf69dd 100644
--- a/src/gui_x11.c
+++ b/src/gui_x11.c
@@ -1167,7 +1167,7 @@
      * Move all the entries in argv which are relevant to X into gui_argv.
      */
     gui_argc = 0;
-    gui_argv = (char **)lalloc(*argc * sizeof(char *), FALSE);
+    gui_argv = LALLOC_MULT(char *, *argc);
     if (gui_argv == NULL)
 	return;
     gui_argv[gui_argc++] = argv[0];