fix Linux compilation

s/build

@@ -2,11 +2,7 @@
 ROOT=$(git rev-parse --show-toplevel)
 BUILD=build
 if [ -z "$JOBS" ] ; then
-  if [ -e /usr/sbin/sysctl ]; then
-    JOBS=`sysctl -n hw.ncpu`
-  else
-    JOBS=`nproc`
-  fi
+  JOBS=`nproc`
 fi
 DISTCC=`which distcc`
 if [ ! -z "$DISTCC" ] ; then

src/battle.c

@@ -3018,11 +3018,6 @@ static void print_stats(battle * b)
     }
 }
 
-static int weapon_weight(const weapon * w)
-{
-    return w->attackskill + w->defenseskill;
-}
-
 side * get_side(battle * b, const struct unit * u)
 {
     side * s;
@@ -3092,8 +3087,8 @@ static void equip_weapons(fighter* fig)
     item* itm;
     unit* u = fig->unit;
     int wpless = weapon_skill(NULL, u, true);
-    size_t w;
-    int p_melee = 0, p_missile = 0, i;
+    size_t w, i;
+    int p_melee = 0, p_missile = 0;
 
     fig->weapons = NULL;
     for (itm = u->items; itm; itm = itm->next) {

src/battle.h

@@ -6,6 +6,7 @@
 
 struct message;
 struct selist;
+struct weapon_type;
 union variant;
 
 /** more defines **/

src/tests.c

@@ -48,7 +48,6 @@
 
 #include <assert.h>
 #include <errno.h>
-#include <stdarg.h>
 #include <stdbool.h>           // for true
 #include <stdio.h>             // for fprintf, stderr
 #include <stdlib.h>