ipv4: Remove dead code in ip4addr_aton()

Use a default case with an assertion to get rid of dead code.

Author: sebhub

src/core/ipv4/ip4_addr.c

@@ -216,10 +216,8 @@ ip4addr_aton(const char *cp, ip4_addr_t *addr)
    */
   switch (pp - parts + 1) {
 
-    case 0:
-      return 0;       /* initial nondigit */
-
-    case 1:             /* a -- 32 bits */
+    default:            /* a -- 32 bits */
+      LWIP_ASSERT("unhandled", pp == parts);
       break;
 
     case 2:             /* a.b -- 8.24 bits */
@@ -251,9 +249,6 @@ ip4addr_aton(const char *cp, ip4_addr_t *addr)
       }
       val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
       break;
-    default:
-      LWIP_ASSERT("unhandled", 0);
-      break;
   }
   if (addr) {
     ip4_addr_set_u32(addr, lwip_htonl(val));