[trivial] clear stack variable by function

Author: isle2983

src/ecmult_gen_impl.h

@@ -150,7 +150,7 @@ static void secp256k1_ecmult_gen(const secp256k1_ecmult_gen_context *ctx, secp25
         secp256k1_ge_from_storage(&add, &adds);
         secp256k1_gej_add_ge(r, r, &add);
     }
-    bits = 0;
+    secp256k1_int_clear(&bits);
     secp256k1_ge_clear(&add);
     secp256k1_scalar_clear(&gnb);
 }

src/group_impl.h

@@ -213,6 +213,10 @@ static void secp256k1_ge_clear(secp256k1_ge *r) {
     secp256k1_fe_clear(&r->y);
 }
 
+static void secp256k1_int_clear(int *r) {
+    *r = 0;
+}
+
 static int secp256k1_ge_set_xquad(secp256k1_ge *r, const secp256k1_fe *x) {
     secp256k1_fe x2, x3, c;
     r->x = *x;