tests: remove secp256k1_fe_verify from tests.c and modify secp256k1_fe_from_storage to call secp256k1_fe_verify

1. secp256k1_fe_verify is removed from tests since, it throws an error if VERIFY is not defined during compilation.
   (Ex: ./configure --enable-coverage)
2. `secp256k1_fe_from_storage` calls `secp256k1_fe_verify` in the VERIFY build to check for invalid field element.

Author: siv2r

src/field_10x26_impl.h

@@ -1162,6 +1162,7 @@ static SECP256K1_INLINE void secp256k1_fe_from_storage(secp256k1_fe *r, const se
 #ifdef VERIFY
     r->magnitude = 1;
     r->normalized = 1;
+    secp256k1_fe_verify(r);
 #endif
 }
 

src/field_5x52_impl.h

@@ -496,6 +496,7 @@ static SECP256K1_INLINE void secp256k1_fe_from_storage(secp256k1_fe *r, const se
 #ifdef VERIFY
     r->magnitude = 1;
     r->normalized = 1;
+    secp256k1_fe_verify(r);
 #endif
 }
 

src/tests.c

@@ -3435,8 +3435,6 @@ void test_pre_g_table(const secp256k1_ge_storage * pre_g, size_t n) {
     CHECK(0 < n);
 
     secp256k1_ge_from_storage(&p, &pre_g[0]);
-    secp256k1_fe_verify(&p.x);
-    secp256k1_fe_verify(&p.y);
     CHECK(secp256k1_ge_is_valid_var(&p));
 
     secp256k1_gej_set_ge(&g2, &p);
@@ -3449,8 +3447,6 @@ void test_pre_g_table(const secp256k1_ge_storage * pre_g, size_t n) {
         CHECK(!secp256k1_fe_normalizes_to_zero_var(&dpx) || !secp256k1_fe_normalizes_to_zero_var(&dpy));
 
         secp256k1_ge_from_storage(&q, &pre_g[i]);
-        secp256k1_fe_verify(&q.x);
-        secp256k1_fe_verify(&q.y);
         CHECK(secp256k1_ge_is_valid_var(&q));
 
         secp256k1_fe_negate(&dqx, &q.x, 1); secp256k1_fe_add(&dqx, &gg.x); secp256k1_fe_normalize_weak(&dqx);