another try at removing static analyzer complaints

The one in options hasn't been addressed this time.

src/bones.c

@@ -471,6 +471,7 @@ savebones(int how, time_t when, struct obj *corpse)
            to be given here, but it has been moved to done() so that
            it gets delivered even when savebones() isn't called] */
         drop_upon_death(mtmp, (struct obj *) 0, u.ux, u.uy);
+        assert(mtmp != NULL && mtmp->data != NULL); /* static analysis hack */
         /* 'mtmp' now has hero's inventory; if 'mtmp' is a mummy, give it
            a wrapping unless already carrying one */
         if (mtmp->data->mlet == S_MUMMY && !m_carrying(mtmp, MUMMY_WRAPPING))

sys/unix/unixunix.c

@@ -370,9 +370,6 @@ int
 child(int wt)
 {
     int f;
-#ifdef CHDIR
-    const char *home = getenv("HOME");
-#endif
 
     suspend_nhwindows((char *) 0); /* also calls end_screen() */
 #ifdef _M_UNIX
@@ -382,6 +379,9 @@ child(int wt)
     linux_mapon();
 #endif
     if ((f = fork()) == 0) { /* child */
+#ifdef CHDIR
+        const char *home = getenv("HOME");
+#endif
         (void) setgid(getgid());
         (void) setuid(getuid());
 #ifdef CHDIR