crypto/elliptic: fix some typos

Author: jaychenthinkfast

src/crypto/elliptic/p256.go

@@ -327,7 +327,7 @@ func p256ReduceDegree(out *[p256Limbs]uint32, tmp [17]uint64) {
 	var tmp2 [18]uint32
 	var carry, x, xMask uint32
 
-	// tmp contains 64-bit words with the same 29,28,29-bit positions as an
+	// tmp contains 64-bit words with the same 29,28,29-bit positions as a
 	// field element. So the top of an element of tmp might overlap with
 	// another element two positions down. The following loop eliminates
 	// this overlap.

src/crypto/elliptic/p256_asm_ppc64le.s

@@ -870,7 +870,7 @@ TEXT ·p256FromMont(SB), NOSPLIT, $0-48
  *                                                                *Mi obra de arte de siglo XXI @vpaprots
  *
  *
- * First group is special, doesnt get the two inputs:
+ * First group is special, doesn't get the two inputs:
  *                                             +--------+--------+<-+
  *                                     +-------|  ADD2  |  ADD1  |--|-----+
  *                                     |       +--------+--------+  |     |