clang-tidy: use auto

src/decoder/DecoderAPI.cxx

@@ -46,7 +46,7 @@ size_t
 decoder_read_much(DecoderClient *client, InputStream &is,
 		  void *_buffer, size_t size) noexcept
 {
-	uint8_t *buffer = (uint8_t *)_buffer;
+	auto buffer = (uint8_t *)_buffer;
 
 	size_t total = 0;
 
@@ -67,7 +67,7 @@ bool
 decoder_read_full(DecoderClient *client, InputStream &is,
 		  void *_buffer, size_t size) noexcept
 {
-	auto *buffer = (uint8_t *)_buffer;
+	auto buffer = (uint8_t *)_buffer;
 
 	while (size > 0) {
 		size_t nbytes = decoder_read(client, is, buffer, size);

src/io/FileDescriptor.cxx

@@ -291,7 +291,7 @@ FileDescriptor::GetSize() const noexcept
 void
 FileDescriptor::FullRead(void *_buffer, size_t length)
 {
-	auto *buffer = (uint8_t *)_buffer;
+	auto buffer = (uint8_t *)_buffer;
 
 	while (length > 0) {
 		ssize_t nbytes = Read(buffer, length);
@@ -309,7 +309,7 @@ FileDescriptor::FullRead(void *_buffer, size_t length)
 void
 FileDescriptor::FullWrite(const void *_buffer, size_t length)
 {
-	const uint8_t *buffer = (const uint8_t *)_buffer;
+	auto buffer = (const uint8_t *)_buffer;
 
 	while (length > 0) {
 		ssize_t nbytes = Write(buffer, length);