Clean warnings when all warning enabled (#2112)

* Clean warnings when all warning enabled

Not used variables / functions due to debug log

Dual define with different values :
cores\esp32/binary.h
#define B110 6
#define B1000000 64

tools/sdk/include/newlib/sys/termios.h
#define B110        3
#define B1000000   23

Local variable returned in WiFiclient Secure

* change due to deprecated function

* Update with proper variable and label

* Update esp32-hal-i2c.c

* Apply changes requested

* Fix warnings due to #define conflict thanks @atanisoft

Author: Luc

src/WiFiClientSecure.cpp

@@ -232,18 +232,19 @@ bool WiFiClientSecure::verify(const char* fp, const char* domain_name)
 }
 
 char *WiFiClientSecure::_streamLoad(Stream& stream, size_t size) {
-  char *dest = (char*)malloc(size);
+  static char *dest = nullptr;
+  if(dest) {
+      free(dest);
+  }
+  dest = (char*)malloc(size);
   if (!dest) {
     return nullptr;
   }
   if (size != stream.readBytes(dest, size)) {
     free(dest);
-    return nullptr;
+    dest = nullptr;
   }
-  char ret[size+1];
-  snprintf(ret, size, "%s", dest);
-  free(dest);
-  return ret;
+  return dest;
 }
 
 bool WiFiClientSecure::loadCACert(Stream& stream, size_t size) {
@@ -290,4 +291,4 @@ int WiFiClientSecure::lastError(char *buf, const size_t size)
 void WiFiClientSecure::setHandshakeTimeout(unsigned long handshake_timeout)
 {
     sslclient->handshake_timeout = handshake_timeout * 1000;
-}
+}