Pass old element to empfile callback prewrite()

Change sct_prewrite(), shp_prewrite(), pln_prewrite(), lnd_prewrite(),
nuk_prewrite() accordingly.  New argument isn't used for anything,
yet.

src/lib/subs/fileinit.c

@@ -42,7 +42,7 @@
 struct fileinit {
     int ef_type;
     void (*postread) (int, void *);
-    void (*prewrite) (int, void *);
+    void (*prewrite) (int, void *, void *);
 };
 
 static struct fileinit fileinit[] = {

src/lib/subs/land.c

@@ -109,9 +109,9 @@ lnd_postread(int n, void *ptr)
 }
 
 void
-lnd_prewrite(int n, void *ptr)
+lnd_prewrite(int n, void *old, void *new)
 {
-    struct lndstr *llp = ptr;
+    struct lndstr *llp = new;
     struct lndstr *lp;
     struct plnstr *pp;
     int i;

src/lib/subs/nuke.c

@@ -74,9 +74,9 @@ nuk_postread(int n, void *ptr)
 }
 
 void
-nuk_prewrite(int n, void *ptr)
+nuk_prewrite(int n, void *old, void *new)
 {
-    struct nukstr *np = ptr;
+    struct nukstr *np = new;
 
     if (np->nuk_effic == 0) {
 	if (np->nuk_own)

src/lib/subs/plane.c

@@ -108,9 +108,9 @@ pln_postread(int n, void *ptr)
 }
 
 void
-pln_prewrite(int n, void *ptr)
+pln_prewrite(int n, void *old, void *new)
 {
-    struct plnstr *pp = ptr;
+    struct plnstr *pp = new;
     struct nukstr *np;
     int i;
 

src/lib/subs/sect.c

@@ -59,9 +59,9 @@ sct_postread(int id, void *ptr)
 }
 
 void
-sct_prewrite(int id, void *ptr)
+sct_prewrite(int id, void *old, void *new)
 {
-    struct sctstr *sp = ptr;
+    struct sctstr *sp = new;
     int mil, civs;
     natid own;
 

src/lib/subs/ship.c

@@ -62,9 +62,9 @@ shp_postread(int n, void *ptr)
 }
 
 void
-shp_prewrite(int n, void *ptr)
+shp_prewrite(int n, void *old, void *new)
 {
-    struct shpstr *sp = ptr;
+    struct shpstr *sp = new;
     struct lndstr *lp;
     struct plnstr *pp;
     int i;