Rename MAKE_FARPTR (and similar) to MAKE_FLATPTR.

The term "far pointer" is used in many 16bit specs, and it is
    different from what MAKE_FARPTR creates.  So, use the term "flat
    pointer" in the code to distinguish between the two meanings.
Also, use the suffix "_fl" consistently when working with "flat
    pointers".
diff --git a/src/boot.c b/src/boot.c
index e0fb67a..142544b 100644
--- a/src/boot.c
+++ b/src/boot.c
@@ -36,11 +36,11 @@
     printf("%s", drivetypes[type]);
 
     /* print product string if BEV */
-    char *far_description = IPL.table[bootdev].description;
-    if (type == 4 && far_description != 0) {
+    char *description_fl = IPL.table[bootdev].description;
+    if (type == 4 && description_fl != 0) {
         char description[33];
         /* first 32 bytes are significant */
-        memcpy_far(MAKE_FARPTR(GET_SEG(SS), description), far_description, 32);
+        memcpy_fl(MAKE_FLATPTR(GET_SEG(SS), description), description_fl, 32);
         /* terminate string */
         description[32] = 0;
         printf(" [%.s]", description);