Silence some compiler warnings

src/mhitm.c

@@ -293,7 +293,7 @@ register struct monst *magr, *mdef;
 {
     int i,          /* loop counter */
         tmp,        /* amour class difference */
-        strike,     /* hit this attack */
+        strike = 0, /* hit this attack */
         attk,       /* attack attempted this time */
         struck = 0, /* hit at least once */
         res[NATTK]; /* results of all attacks */

src/mhitu.c

@@ -349,7 +349,7 @@ mattacku(mtmp)
 register struct monst *mtmp;
 {
     struct attack *mattk, alt_attk;
-    int i, j, tmp, sum[NATTK];
+    int i, j = 0, tmp, sum[NATTK];
     struct permonst *mdat = mtmp->data;
     boolean ranged = (distu(mtmp->mx, mtmp->my) > 3);
     /* Is it near you?  Affects your actions */